Delicious Oatmeal Monster Cookies

Here’s my tried-and-true recipe for oatmeal monster cookies, packed with hearty oats, chocolate chips, M&Ms, and just enough peanut butter to hold everything together in one deliciously chewy treat.

These monster cookies are a regular feature in our cookie jar, and for good reason – they disappear faster than any other cookie I make. I always double the batch because my kids claim they taste even better the next day (if they last that long!).

What Kind of Oats Should I Use?

While this recipe calls for traditional rolled oats (sometimes labeled as “old-fashioned oats”), you might be wondering about using quick oats instead. Stick with the traditional rolled oats here – they give these monster cookies their signature chewy texture and hearty bite that quick oats just can’t match. Steel-cut oats aren’t a good substitute in this recipe since they’re too firm and won’t soften properly while baking. If you’re buying oats specifically for baking, look for containers marked “old-fashioned” or “rolled” – these are exactly what you need for the best cookie texture. Just make sure your oats are fresh by giving them a quick sniff test, as they can go stale or rancid if stored too long.

Options for Substitutions

These fun cookies are pretty adaptable! Here are some swaps you can try:

• Butter: You can use coconut oil (in solid form) or margarine instead of butter. Just make sure they’re at room temperature before mixing.
• Peanut butter: Not a fan of peanut butter or have allergies? Try almond butter, sunflower seed butter, or cashew butter instead. Each will give a slightly different but equally good flavor.
• Traditional rolled oats: Quick oats can work in a pinch, but the texture won’t be quite the same. Don’t use instant oats though – they’re too finely ground and will change the cookie structure.
• M&Ms and chocolate chips: Feel free to mix and match your add-ins! Try Reese’s Pieces, chopped nuts, raisins, or different flavored chips. Just keep the total amount to about 1 1/4 cups.
• Egg: For a vegan version, you can use a flax egg (1 tablespoon ground flaxseed mixed with 3 tablespoons water, let sit for 5 minutes) or a mashed banana.
• Plain flour: For a gluten-free option, use a 1:1 gluten-free flour blend. Just make sure it contains xanthan gum for the right texture.

Watch Out for These Mistakes While Baking

The biggest challenge with oatmeal monster cookies is overmixing the dough, which can make your cookies tough and dense – mix just until the ingredients are combined to keep them soft and chewy. Getting the butter temperature right is crucial too – if it’s too soft or melted, your cookies will spread too much and become flat; the butter should be just soft enough to leave a slight indent when pressed. Another common mistake is overbaking these treats – they might look slightly underdone when you take them out at 10-12 minutes, but they’ll continue cooking on the hot baking sheet, so remove them when the edges are just set and the centers still look a bit puffy. For the best texture, let the cookies cool on the baking sheet for 5 minutes before moving them to a wire rack – this allows them to set properly without breaking apart.

What to Serve With Monster Cookies?

These sweet and hearty cookies are perfect with a cold glass of milk – it’s a classic combo that never gets old! Since monster cookies are packed with oats, peanut butter, and lots of chocolate, they pair really nicely with hot beverages too, like coffee or hot chocolate. For an after-school snack, I like serving these cookies alongside some fresh fruit like strawberries or apple slices to balance out the sweetness. If you’re putting together a dessert platter, these cookies work great next to some vanilla ice cream for a make-your-own ice cream sandwich station.

Storage Instructions

Keep Fresh: These monster cookies stay perfectly chewy when stored in an airtight container at room temperature. They’ll keep well for up to 5 days – if they last that long! I like to add a piece of bread to the container to help maintain their soft texture.

Freeze Baked: Already baked cookies? No problem! Place them in a freezer-safe container with parchment paper between layers and they’ll keep for up to 3 months. Perfect for when you want just one or two cookies at a time!

Freeze Dough: You can also freeze the cookie dough for later. Shape into balls, place them on a baking sheet to freeze until solid, then transfer to a freezer bag. When ready to bake, just add 1-2 minutes to the original baking time – no need to thaw! The dough keeps well for up to 3 months.

Preparation Time	15-20 minutes
Cooking Time	10-15 minutes
Total Time	25-35 minutes
Level of Difficulty	Easy

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

• Calories: 2200-2400
• Protein: 30-35 g
• Fat: 100-110 g
• Carbohydrates: 300-320 g

Ingredients

• 1/2 cup granulated sugar
• 1/2 cup semi-sweet chocolate chips (good quality like Ghirardelli for melting)
• 1 egg
• 3/4 cup M&M candies
• 1/2 cup softened butter (unsalted, at room temperature for creaming)
• 1 tsp vanilla extract (pure vanilla extract for best flavor)
• 1/4 tsp salt
• 1/2 cup packed brown sugar (light or dark brown sugar will work here)
• 1/2 tsp baking soda
• 1 1/4 cups rolled oats (old-fashioned rolled oats, not instant)
• 1/2 tsp baking powder
• 1 cup all-purpose flour
• 1/2 cup creamy peanut butter (I like Jif creamy peanut butter)

Step 1: Preheat the Oven

Begin by preheating your oven to 350 degrees F (175 degrees C).

This ensures that your cookies bake evenly and to perfection.

Step 2: Cream Butter and Sugar

In a large mixing bowl, cream together the butter and sugar.

It’s important to beat them really well for at least 2-3 minutes until the mixture is light and fluffy.

This step is crucial for incorporating air into the dough, which helps in creating soft cookies.

Step 3: Combine Wet Ingredients

Add the peanut butter to the creamed mixture and mix well.

Follow this by adding the egg and vanilla extract, mixing until all the ingredients are combined smoothly.

Step 4: Mix Dry Ingredients

In a separate bowl, combine the dry ingredients.

Stir together the flour, oats, salt, baking powder, and baking soda.

Be sure to measure the flour correctly by spooning it into a measuring cup and leveling it off for accuracy.

This helps avoid too dense cookies.

Step 5: Form the Cookie Dough

Add the dry ingredients to the wet mixture and mix until well combined.

Gently stir in the chocolate chips and M&M’s, ensuring they’re evenly distributed throughout the dough.

Step 6: Bake the Cookies

Using a 1-inch cookie scoop, place dough onto a baking sheet lined with parchment paper.

Bake in the preheated oven for 10-12 minutes, extending time slightly for larger cookies if needed.

Avoid over-baking; the cookies should look just set.

Step 7: Cool Completely

Remove the cookies from the oven and allow them to cool completely on the pan.

This step helps the cookies firm up and develop a delightful texture.

Once cooled, enjoy your homemade treats!