Monster Cookies
Monster Cookies are a fun and colorful treat loaded with peanut butter, oats, chocolate chips, and those classic candy-coated chocolates that give each bite a delightful pop of color and…
Tip: save now, cook later.Monster Cookies are a fun and colorful treat loaded with peanut butter, oats, chocolate chips, and those classic candy-coated chocolates that give each bite a delightful pop of color and crunch. They’re chewy, gooey, and packed with so many tasty bits that every cookie feels like a little celebration in your mouth.
I love making these especially when I want something quick but satisfying to share. The mix of textures—from the softness of the cookie to the crunch of the candies and the slight chewiness of oats—keeps me coming back for more. I always tell my friends that if you’re having a rough day, a monster cookie can make things a little better.
My favorite way to enjoy them is with a cold glass of milk in the afternoon, almost like a sweet little break between tasks. They’re perfect for packing in lunchboxes or bringing to gatherings because everyone seems to love their colorful, fun vibe. These cookies always bring big smiles no matter where or when you eat them!
Key Ingredients & Substitutions
Peanut Butter: This gives the cookies their signature rich and nutty flavor. If you have a peanut allergy, sunflower seed butter is a great substitute that keeps the creamy texture.
Oats: Rolled oats add chewiness and a hearty texture. Instant oats work too but the cookie will be softer. For gluten-free, make sure to use certified gluten-free oats.
Chocolate Chips & M&M’s: Use semisweet chips to balance sweetness. For allergy-friendly versions, try carob chips. Candy-coated chocolates add color and crunch, but you can omit or substitute with chopped nuts or dried fruit.
Food Coloring: Totally optional and just for fun to create those bright monster colors. You can skip it without changing the flavor.
How Do You Keep Monster Cookies Soft and Chewy?
Soft and chewy texture is key to great monster cookies. Here’s how to get it:
- Cream the butters and sugars well: This traps air and gives a light texture.
- Don’t overmix once flour is added: Mix until just combined to avoid tough cookies.
- Bake just until edges set: Take them out when the cookies look slightly underbaked in the center—they’ll firm up as they cool.
- Use rolled oats: They add chewiness without drying out the cookie.
These tips help keep your monster cookies tender and full of gooey peanut butter goodness every time!

Equipment You’ll Need
- Mixing bowls – a large one for the dough and a smaller one for dry ingredients makes mixing easier.
- Electric mixer or sturdy wooden spoon – to cream butter and sugars smoothly.
- Measuring cups and spoons – for accurate ingredient amounts and a consistent cookie texture.
- Baking sheets – choose heavy-duty or rimmed ones to hold the cookie dough and prevent spills.
- Parchment paper or silicone baking mats – helps prevent sticking and makes cleanup simple.
- Cookie scoop or spoon – for evenly sized cookies that bake uniformly.
- Cooling rack – lets cookies cool evenly and prevents sogginess.
Flavor Variations & Add-Ins
- Swap peanut butter with almond or cashew butter for a milder, nutty flavor that still keeps the chewiness.
- Stir in chopped nuts like walnuts or pecans for extra crunch and a natural twist.
- Add dried cranberries or raisins to balance the sweetness with a bit of tartness.
- Use white chocolate chips or butterscotch chips instead of semisweet for a sweeter, creamier bite.
How to Make Monster Cookies
Ingredients You’ll Need:
Main Ingredients:
- 1 cup unsalted butter, softened
- 1 cup crunchy peanut butter
- 1 cup granulated sugar
- 1 cup packed brown sugar
- 2 large eggs
- 2 ½ cups all-purpose flour
- 1 teaspoon baking soda
- ½ teaspoon salt
- 3 cups old-fashioned rolled oats
- 1 ½ cups semisweet chocolate chips (plus extra for decorating)
- 1 cup M&M’s or candy-coated chocolates (in various colors, plus extra to decorate)
Decorations and Extras:
- Food coloring (blue and orange) – optional for coloring dough for a fun monster look
- Candy eyes (large edible eyeball candies)
- White chocolate or almond slivers for monster teeth
- Melted chocolate or chocolate decorating gel for drawing faces
Time Needed
Preparation takes about 15 minutes, baking time is 12-14 minutes per batch, and you’ll want to allow an additional 10-15 minutes for decorating and cooling. Overall, set aside about 40 minutes from start to finish.
Step-by-Step Instructions:
1. Preparing Your Oven and Baking Sheets:
Start by preheating your oven to 350°F (175°C). Line your baking sheets with parchment paper or silicone baking mats to keep cookies from sticking and make cleaning up easier.
2. Making the Cookie Dough:
In a large mixing bowl, cream the softened butter, crunchy peanut butter, granulated sugar, and brown sugar together until smooth and fluffy. Next, beat in the eggs one at a time, mixing well each time. In a separate bowl, whisk the flour, baking soda, and salt. Gradually add the dry ingredients to the wet mixture, stirring until just combined. Then fold in the oats, chocolate chips, and M&M’s.
3. Coloring the Dough (Optional):
If you want your cookies to have those bright monster colors, divide the dough into portions and mix in blue or orange food coloring until the color is even.
4. Baking the Cookies:
Using a large cookie scoop or spoon, place the dough onto the baking sheets about 2 inches apart. Bake for 12-14 minutes, until the edges are set and the cookies start to turn golden. Remove the cookies from the oven and let them cool on the baking sheets for a few minutes before moving to a wire rack.
5. Decorating Your Monster Cookies:
While still a bit warm, gently press candy eyes onto the tops of the cookies. Use melted chocolate or decorating gel to draw monster mouths, and add white chocolate or almond slivers for teeth. Let the decorations set completely before serving.
Enjoy your colorful, chewy, and fun Monster Cookies! They are perfect for sharing or just treating yourself.
Can I Use Natural Peanut Butter Instead of Crunchy?
Yes! Natural peanut butter works, but it may make the dough a bit softer and the cookies slightly less crunchy. You might want to chill the dough before baking to help with spreading.
Can I Make the Dough Ahead of Time?
Absolutely! You can prepare the dough and store it in the refrigerator for up to 3 days or freeze it for up to 3 months. Just thaw in the fridge overnight before baking.
How Should I Store Leftover Monster Cookies?
Keep leftover cookies in an airtight container at room temperature for up to 5 days. For longer storage, freeze them in a sealed bag or container for up to 2 months.
What Can I Use if I Don’t Have Candy Eyes?
No worries! You can use small chocolate chips, raisins, or even draw eyes with melted chocolate or icing. Feel free to get creative with what you have on hand!