Big, soft cookies like these OMG Peanut Butter Marshmallow Cookies are sure to impress at any gathering. With their gooey marshmallows, chunks of Reese’s Peanut Butter Cups, and a blend of rich chocolate, these cookies are perfect for parties, family get-togethers, or simply satisfying your sweet tooth. The combination of flavors and textures makes each bite a delightful experience!

Jump to:
- Why You’ll Love This Recipe
- Tools and Preparation
- Essential Tools and Equipment
- Importance of Each Tool
- Ingredients
- For the Cookie Dough
- For Mix-Ins
- How to Make OMG Peanut Butter Marshmallow Cookies
- Step 1: Preheat the Oven
- Step 2: Mix the Wet Ingredients
- Step 3: Add Dry Ingredients
- Step 4: Fold in the Goodies
- Step 5: Scoop the Dough
- Step 6: Flatten Each Scoop
- Step 7: Bake
- Step 8: Cool Down
- How to Serve OMG Peanut Butter Marshmallow Cookies
- With a Glass of Milk
- Ice Cream Sandwiches
- Warmed Up
- Topped with Whipped Cream
- Cookie Platter
- Coffee Pairing
- How to Perfect OMG Peanut Butter Marshmallow Cookies
- Best Side Dishes for OMG Peanut Butter Marshmallow Cookies
- Common Mistakes to Avoid
- Storage & Reheating Instructions
- Refrigerator Storage
- Freezing OMG Peanut Butter Marshmallow Cookies
- Reheating OMG Peanut Butter Marshmallow Cookies
- Frequently Asked Questions
- What makes OMG Peanut Butter Marshmallow Cookies so special?
- Can I customize my OMG Peanut Butter Marshmallow Cookies?
- How long do OMG Peanut Butter Marshmallow Cookies last?
- Can I make these cookies gluten-free?
- Final Thoughts
- 📖 Recipe Card
Why You’ll Love This Recipe
- Irresistible Flavor: The mix of peanut butter, chocolate, and marshmallows creates a flavor explosion that everyone loves.
- Easy to Make: With simple ingredients and straightforward steps, even beginner bakers can whip these up with ease.
- Perfect for Any Occasion: Whether it’s a birthday party or a cozy night in, these cookies fit right in.
- Customization Options: Feel free to adjust the mix-ins to suit your taste—add nuts or swap out chocolates!
- Jumbo Size: These cookies are big and hearty, making them an indulgent treat that satisfies.
Tools and Preparation
Gathering the right tools will make your baking experience smooth and enjoyable. Here’s what you’ll need:
Essential Tools and Equipment
- Stand mixer or hand mixer
- Mixing bowls
- Measuring cups and spoons
- Baking sheets
- Parchment paper
- Ice cream scoop
Importance of Each Tool
- Stand mixer or hand mixer: Makes it easy to combine ingredients thoroughly without much effort.
- Parchment paper: Prevents sticking and helps achieve perfectly baked cookies without mess.
Ingredients
Hello! Big, soft peanut butter cookies loaded with toast marshmallows, Reese’s Peanut Butter Cups, rich milk chocolate and peanut butter chips! Trust me, these cookies are not going too last long!
For the Cookie Dough
- 3/4 cup unsalted butter (softened)
- 3/4 cup granulated sugar
- 1 cup brown sugar
- 1 cup peanut butter (creamy or crunchy)
- 2 large eggs
- 1 tablespoon vanilla extract
- 2 1/2 cups all-purpose flour
- 1 teaspoon baking soda
- 1/2 teaspoon salt
For Mix-Ins
- 1 1/2 – 2 cups mini marshmallows
- 1 bag of Mini Reese’s Peanut Butter Cups (chopped coarsely or whole)
- 1 cup Reese’s Peanut Butter Chips
- 1 cup Ghirardelli Milk Chocolate Chips (or Semi-sweet Chocolate Chips)

How to Make OMG Peanut Butter Marshmallow Cookies
Step 1: Preheat the Oven
Preheat your oven to 350°F (175°C). This ensures that your cookies bake evenly.
Step 2: Mix the Wet Ingredients
Using a mixer:
1. Combine the softened butter, granulated sugar, brown sugar, peanut butter, eggs, and vanilla extract.
2. Mix until everything is well combined.
Step 3: Add Dry Ingredients
Add the flour, baking soda, and salt. Mix until just combined; be careful not to overmix.
Step 4: Fold in the Goodies
Gently fold in:
– Mini marshmallows
– Chopped Reese’s Peanut Butter Cups
– Peanut butter chips
– Milk chocolate chips
Step 5: Scoop the Dough
Using an ice cream scoop:
– Scoop dough onto parchment-lined cookie sheets. Place about six per sheet as these will be large cookies.
– Optionally roll into balls for a more uniform shape.
Step 6: Flatten Each Scoop
Slightly flatten each scoop of dough with your hand. This helps them spread nicely while baking.
Step 7: Bake
Bake for 10–12 minutes at 350°F. If you chilled your dough beforehand, add a couple of extra minutes to the baking time.
Step 8: Cool Down
Remove from oven and let cookies cool on the baking sheet for about 5–10 minutes before transferring them to a cooling rack. They need time to set up properly; otherwise they may fall apart when moved too soon.
Enjoy your delicious OMG Peanut Butter Marshmallow Cookies!
How to Serve OMG Peanut Butter Marshmallow Cookies
Serving your OMG Peanut Butter Marshmallow Cookies can elevate the experience and delight your guests. Here are some fun and creative ways to enjoy these delicious treats.
With a Glass of Milk
- A classic pairing! The creaminess of milk enhances the rich flavors of the cookies.
Ice Cream Sandwiches
- Use two cookies to create a delicious ice cream sandwich, adding your favorite flavor for an indulgent treat.
Warmed Up
- Slightly warm cookies bring out the gooey chocolate and marshmallows. Just pop them in the microwave for a few seconds before serving.
Topped with Whipped Cream
- Add a dollop of whipped cream on top for a decadent dessert option that’s perfect for special occasions.
Cookie Platter
- Arrange your cookies on a platter with other desserts, like brownies or cake bites, for a delightful dessert buffet.
Coffee Pairing
- Pair these cookies with a strong cup of coffee or mocha for an adult twist on dessert time.
How to Perfect OMG Peanut Butter Marshmallow Cookies
To ensure your OMG Peanut Butter Marshmallow Cookies turn out perfectly every time, follow these helpful tips:
- Use room temperature ingredients: This helps create a smoother dough and ensures even mixing.
- Don’t overmix the dough: Mix just until combined to keep the cookies tender.
- Chill the dough: Chilling for at least 30 minutes helps prevent spreading and results in thicker cookies.
- Watch baking time closely: Every oven is different; keep an eye on your cookies as they bake to avoid overcooking.
- Let them cool properly: Allowing the cookies to cool on the baking sheet helps them set without falling apart.
- Experiment with mix-ins: Feel free to add nuts or other candies to customize your cookie experience!

Best Side Dishes for OMG Peanut Butter Marshmallow Cookies
These cookies are deliciously sweet, so pairing them with complementary side dishes can enhance their flavor profile. Consider these options:
Vanilla Ice Cream
A scoop of vanilla ice cream adds creaminess that balances the sweetness of the cookies.Chocolate Fondue
Serve alongside melted chocolate for dipping, creating a fun interactive dessert experience.Fruit Salad
Fresh fruit provides a refreshing contrast to the rich flavors of peanut butter and chocolate.Cheese Platter
A selection of cheeses can add an interesting savory note that pairs well with sweet desserts.Coffee Cake
The crumbly texture of coffee cake complements these soft cookies while providing variety.Milkshake
A thick milkshake made with chocolate or peanut butter complements the flavors in each cookie bite.Yogurt Parfait
Layer yogurt with granola and fruits as a light side that balances out the richness of the cookies.Peanut Butter Dip with Pretzels
This salty-sweet combination enhances peanut butter’s flavor while offering a crunchy contrast to soft cookies.
Common Mistakes to Avoid
Making OMG Peanut Butter Marshmallow Cookies can be a delightful experience, but a few common mistakes might hinder your cookie perfection. Here are some pitfalls to avoid.
- Using cold ingredients: Cold butter and eggs can lead to uneven mixing. Always use softened butter and bring eggs to room temperature for the best texture.
- Overmixing the dough: Overmixing can make cookies tough. Mix only until ingredients are combined to keep them soft and chewy.
- Skipping the chilling step: Chilling the dough allows flavors to meld and helps prevent cookies from spreading too much. If time allows, chill your dough for at least 30 minutes.
- Not measuring flour correctly: Using too much flour can result in dry cookies. Use the spoon-and-level method for accurate measurement.
- Ignoring baking times: Cookies may look underbaked when they’re actually done. Remove them when edges are lightly golden; they will continue to cook as they cool.
Storage & Reheating Instructions
Refrigerator Storage
- Store cookies in an airtight container in the fridge.
- They will stay fresh for up to one week.
Freezing OMG Peanut Butter Marshmallow Cookies
- Place cooled cookies in a single layer on a baking sheet.
- Freeze until solid, then transfer them to a freezer-safe bag or container.
- Frozen cookies can last up to three months.
Reheating OMG Peanut Butter Marshmallow Cookies
- Oven: Preheat to 350°F and bake for 5-7 minutes until warm.
- Microwave: Heat for 10-15 seconds; check frequently to avoid overheating.
- Stovetop: Use a skillet over low heat, covering it with a lid for even warming.

Frequently Asked Questions
What makes OMG Peanut Butter Marshmallow Cookies so special?
These cookies feature a delightful combination of peanut butter, melted marshmallows, and chocolate chips, creating a unique taste and texture that is irresistible.
Can I customize my OMG Peanut Butter Marshmallow Cookies?
Absolutely! You can add nuts, swap out marshmallows for other candies, or use different chocolate types according to your preferences.
How long do OMG Peanut Butter Marshmallow Cookies last?
When stored properly in an airtight container, these cookies can last up to one week in the refrigerator or three months in the freezer.
Can I make these cookies gluten-free?
Yes! Substitute all-purpose flour with a gluten-free blend that works cup-for-cup as an alternative for delicious results.
Final Thoughts
OMG Peanut Butter Marshmallow Cookies are not only delicious but also incredibly versatile. Their rich chocolatey flavor combined with peanut butter makes them perfect for any occasion. Feel free to customize them based on your tastes or dietary needs. Don’t hesitate—try making these delightful treats today!
Did You Enjoy Making This Recipe? Please rate this recipe with ⭐⭐⭐⭐⭐ or leave a comment.
📖 Recipe Card
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OMG Peanut Butter Marshmallow Cookies
- Total Time: 32 minutes
- Yield: Approximately 18 large cookies 1x
Description
Treat yourself and your guests to the ultimate sweet indulgence with OMG Peanut Butter Marshmallow Cookies. These big, soft cookies are a delightful blend of creamy peanut butter, gooey marshmallows, and chunks of Reese’s Peanut Butter Cups, all enveloped in rich chocolate chips. Perfect for any occasion—be it birthday parties, family gatherings, or a cozy night in—these cookies promise to impress with every bite. Simple to make, they invite creativity through customizable mix-ins while their jumbo size guarantees satisfaction. Get ready to bake a batch that will disappear faster than you can say ‘delicious’!
Ingredients
- 3/4 cup unsalted butter (softened)
- 3/4 cup granulated sugar
- 1 cup brown sugar
- 1 cup peanut butter (creamy or crunchy)
- 2 large eggs
- 1 tablespoon vanilla extract
- 2 1/2 cups all-purpose flour
- 1 teaspoon baking soda
- 1/2 teaspoon salt
- 1 1/2 – 2 cups mini marshmallows
- 1 bag Mini Reese’s Peanut Butter Cups (chopped)
- 1 cup Reese’s Peanut Butter Chips
- 1 cup Ghirardelli Milk Chocolate Chips
Instructions
- Preheat your oven to 350°F (175°C).
- In a mixer, combine softened butter, granulated sugar, brown sugar, peanut butter, eggs, and vanilla extract until smooth.
- Add flour, baking soda, and salt; mix until just combined.
- Fold in mini marshmallows, chopped Reese's Cups, peanut butter chips, and chocolate chips.
- Scoop dough onto parchment-lined baking sheets (about six per sheet) and slightly flatten each scoop.
- Bake for 10–12 minutes until edges are golden; cool on the baking sheet for a few minutes before transferring to a wire rack.
- Prep Time: 20 minutes
- Cook Time: 12 minutes
- Category: Dessert
- Method: Baking
- Cuisine: American
Nutrition
- Serving Size: 1 cookie (70g)
- Calories: 330
- Sugar: 24g
- Sodium: 180mg
- Fat: 16g
- Saturated Fat: 6g
- Unsaturated Fat: 8g
- Trans Fat: 0g
- Carbohydrates: 43g
- Fiber: 2g
- Protein: 6g
- Cholesterol: 30mg