How many servings does this recipe make?

This recipe makes 4 servings. You can adjust the portion size directly on this page.

What ingredients do I need for Riley and Chelsea's Favorite Monster Cookies?

You need 11 ingredients. The key ingredients include: 1 ½ cups smooth peanut butter, ½ cup margarine, softened, 1 ½ cups brown sugar, packed, 1 cup white sugar, and more.

Is Riley and Chelsea's Favorite Monster Cookies suitable as baking & desserts?

Yes, Riley and Chelsea's Favorite Monster Cookies falls under the Baking & Desserts category and is a great choice for this type of meal.

How do I store leftover Riley and Chelsea's Favorite Monster Cookies?

Store in an airtight container at room temperature for up to 3–5 days. For longer storage, freeze for up to 3 months — no need to refrigerate or reheat.

Riley and Chelsea's Favorite Monster Cookies Recipe

Name: Riley and Chelsea's Favorite Monster Cookies
Prep time: 15 min
Cook time: 30 min
Total time: 45 min
Yield: 4 servings
Ingredients: 1 ½ cups smooth peanut butter; ½ cup margarine, softened; 1 ½ cups brown sugar, packed; 1 cup white sugar; 3 eggs; ¼ teaspoon vanilla extract; ¼ tablespoon corn syrup; 4 ½ cups rolled oats; 2 teaspoons baking soda; ¾ cup semi-sweet chocolate chips; ¾ cup smarties candies or ¾ cup M&M'

Bake this irresistible Riley and Chelsea's Favorite Monster Cookies at home. Made with smooth peanut butter, margarine, brown sugar and white sugar. Eas…

This Riley and Chelsea's Favorite Monster Cookies relies on simple, everyday ingredients such as smooth peanut butter, margarine, softened, brown sugar, packed and white sugar. It comes together quickly and makes 4 servings, at about 1713 kcal each. The step-by-step instructions below are written to be easy to follow, even on a busy day.

Whether you're rounding off a family dinner, bringing a treat to a gathering, or simply satisfying a sweet craving, this Riley and Chelsea's Favorite Monster Cookies delivers. Serve it warm or at room temperature, and add a scoop of ice cream or a spoonful of whipped cream for an extra-special finish.

Updated Jun 30, 2026

Serves 4 Baking & Desserts

1713

kcal

Calories

Tips for the best results

Read through all the steps once before you start and measure out your ingredients first — it makes everything go more smoothly.
Preheat the oven fully and bake on the middle rack for the most even results.
Check for doneness a few minutes early — a toothpick in the center should come out with just a few moist crumbs.
Let it cool before slicing so it sets properly and holds its shape.
Store leftovers in an airtight container in the fridge and enjoy within a few days.

Variations & substitutions

Use a neutral oil or a plant-based spread in place of butter for a dairy-free version.
Brown sugar instead of white sugar adds a deeper, more caramel-like flavor.

No specific allergen information. Please check the ingredient list for possible allergens.

My Personal Notes

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Riley and Chelsea's Favorite Monster Cookies

Tips for the best results

Variations & substitutions

My Personal Notes

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