Monster Brookies

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Half peanut butter M&M cookie, half brownie cookie — it’s one dreamy dessert combination that you need in your life.

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Monster brookies have been a staple, go-to dessert for me for a long time. Over the years, I’ve made these in both bar and cookie form and they’re always a crowd pleaser. I mean, two of the best desserts combined in one, how could they ever disappoint?!

A dreamy, peanut butter cookie, that’s packed with mini M&Ms and mini chocolate chips, is paired with a decadent, delicious brownie cookie. While traditional brookies will always have a special place in my heart, the peanut butter in these Monster Brookies just takes everything to the next level. If you’re a peanut butter lover, I highly recommend trying these out!

This recipe is super easy to follow and guaranteed to be your new favorite.

Read on for the full recipe for these must-bake Monster Brookies.

As with all of my recipes, my goal is to make the process as quick and easy as possible while still yielding the most amazing dessert. While I will always promote taking the extra time to brown your butter and chill your dough, I still look to find ways to shorten the process and minimize the amount of time in the kitchen.

With that being said, I opted to use melted butter for the base of both cookie doughs. I love the soft and chewy texture that melted butter gives cookies which is a top reason why most of my recipes use it. The other reason is that a stand or hand mixer isn’t required. I’m all for less dishes and I know not everyone has a mixer.

With melted butter, it’s very important that you let it cool before combining it with the sugars. Hot butter will not combine properly with the other ingredients which will impact the texture and may cause the cookies to bake up flat — both things that we do not want. So, be sure to let your butter cool for 10 minutes before whisking it with the brown and granulated sugars.

A few other top tips for this recipe:

• Use room temperature eggs. If you forget to take them out in advance, run them under some warm water (not super hot!) for a few seconds or place them in a bowl with warm water.
• Measure your flour properly (see my note about this in my “Tips for success” section) and do not overmix your cookie dough. Too much flour will result in dry, crumbly cookies and overmixing your dough will impact the texture. I stop mixing my dry ingredients when a few flour streaks are still visible. Then, I gently fold in my toppings until they’re just combined.
• Chill your dough for 25 minutes — but no more than that! We will be briefly chilling the doughs for this recipe, just to help prevent spreading while baking. However, we don’t want to overchill them or else the two doughs may have difficulty sticking to each other when they’re rolled together.

While this recipe does require making two doughs, I promise that they both come together very easily and that it’s absolutely worth it! Get ready to enjoy your new favorite cookies!

Other recipes you may like:

• S’mores Brookies
• Chocolate Dipped Peanut Butter Stuffed Reese’s Cookies
• Oreo Cookie Butter Lava Cookies
• Mini Brookies
• Chocolate Dipped M&M Oreo Cookies

Ingredients you’ll need:

• Unsalted butter
• Brown sugar
• Granulated sugar
• Creamy peanut butter (I used Jif)
• Vanilla extract
• Eggs
• All-purpose flour
• Cocoa powder
• Baking soda
• Salt
• Mini M&Ms
• Mini chocolate chips
• Semisweet chocolate chips

Kitchen tools you’ll need (linking my favorites below!)

• Mixing bowls
• Dry ingredient measuring cups
• Adjustable measuring cups — great for measuring the peanut butter!
• Spatula
• Whisk
• Cookie scoop
• Baking sheet
• Parchment paper
• Cookie turner
• Cooling rack

How to make these delicious Monster Brookies.

Peanut Butter Cookie Dough

Make the peanut butter cookie dough. Melt ½ cup unsalted butter on the stove or in the microwave. Set aside to cool for 10 minutes.

While the butter is cooling, whisk together 1½ cups + 1½ tbsp all-purpose flour, 1 tsp baking soda, and ½ tsp salt in a bowl. Set aside.

In a large bowl, add ½ cup brown sugar, ¼ cup granulated sugar, and the melted butter. Whisk together until it is smooth and fully combined.

Add ¼ cup creamy peanut butter, 1 egg, and 1 tsp vanilla extract. Whisk until the mixture is smooth and fully combined.

Fold in the dry ingredients with a rubber spatula until a few flour streaks remain. Gently fold in 2/3 cup mini M&Ms and 2 tbsp mini chocolate chips.

Set aside the peanut butter cookie dough. Wait to refrigerate and chill at the same time as the brownie cookie dough.

Brownie Cookie Dough

Melt ½ cup unsalted butter. Set aside to cool for 10 minutes.

Whisk together the dry ingredients in a bowl: 1 cup all-purpose flour, ½ cup cocoa powder, 1 tsp baking soda, and ½ tsp salt. Set aside.

In a large bowl, whisk together ½ cup brown sugar, ¼ cup granulated sugar, and the melted butter until it’s fully combined.

Whisk in 1 egg and 1 tsp vanilla extract until incorporated.

Add in the dry ingredients. Gently fold them in with a rubber spatula. Then, fold in 1/3 cup semisweet chocolate chips and 1/3 cup mini chocolate chips. Be careful not to overmix.

Chill both the peanut butter cookie dough and brownie dough at the same time in the refrigerator for 25 minutes. Preheat the oven to 350 degrees Fahrenheit.

Assembly and Baking

Scoop 16 dough balls for each cookie dough. Take one peanut butter cookie dough ball and one brownie cookie dough ball and press them together so they stick together. Roll them together gently.

On a baking sheet lined with parchment paper, bake for 10-12 minutes or until the edges are golden and the tops of the cookies still look slightly wet. As soon as they come out of the oven, top with extra mini M&Ms and chocolate chips, if desired.

Let the cookies cool completely. Store in an airtight container for up to 5 days or freeze for up to 3 months.

Tips for success

• Be sure to measure your dry ingredients correctly. I highly recommend using the spoon and level method. Before scooping out dry ingredients (like flour), use a spoon and run through them, fluffing them up and removing any clumps. Then, spoon the ingredient into the measuring cup and use a flat top tool to level off the top and remove any excess. When measuring dry ingredients, you should always be using measuring cups like these. However, if you prefer to bake using grams and weighing your dry ingredients with a kitchen scale, this recipe can easily be converted using an online conversion calculator like this one from Inch Calculator. I personally bake using volume measurements (cups) which is why I do not include metric conversions.
• Use an adjustable measuring cup to measure your peanut butter. I know you already have so many kitchen tools, but if you don’t have this one, I highly recommend adding it to your list. It really does make life SO much easier.
• Keep in mind that the baking time listed is just a guide. Everyone’s oven is different. Go by how the cookies look instead. The cookies are done baking and should be removed from the oven when the edges are set and lightly golden. The tops of the cookies will still look a little wet, but that’s okay. The cookies will continue baking on the hot pan once they’re removed from the oven. Trust me on this one as nobody wants dry, crumbly cookies.

FAQs

Can I make these cookies smaller or larger?

Yes! If you choose to make these smaller or larger, the baking temperature will remain the same, but you will need to adjust the bake time. If you decide to make larger cookies, start by adding 1-2 minutes to the bake time. If making smaller cookies, start by reducing the bake time by 1-2 minutes. However, always use the bake time as just guidance. Instead, go by how the cookies look. The cookies should be removed from the oven when the edges are wet and lightly golden. The tops of the cookies will still be a little wet.

Do I have to chill the dough?

You don’t have to, but I highly recommend it. Chilling the dough helps ensure that the cookie dough doesn’t spread too much while baking. As a result, the cookies will bake up with some height and thickness. I don’t recommend chilling the cookie doughs for more than 25 minutes.

Can I make the cookie doughs in advance?

While I haven’t tried it for this recipe, my instinct would be to not make it in advance. I’ve found that 25 minutes of chill time in the refrigerator is the perfect amount for both cookie doughs. If the cookie doughs chill for longer than that, they may not stick together when they’re rolled together. If you do choose to make this dough in advance, chill the doughs for 25 minutes, then scoop and form the cookie dough balls. Once the brookie cookie dough balls have been formed, place them back in the refrigerator — the dough should be good for about 3 days.

How to store

Store the cookies in an airtight container at room temperature for up to 5 days or freeze for up to 3 months. If freezing, store the cookies in a freezer-safe container or bag. Set the cookies out on the counter for 20-30 minutes prior to consuming or pop them in the microwave for about 30 seconds to heat them up.

These cookies are dreamy, decadent, and the perfect combination of chocolate and peanut butter. Plus, they’re such a fun twist on a typical brookie and guaranteed to be a crowd pleaser. Try them out and let me know what you think!

If you try this recipe, share and tag me on socials using @itsbrunchoklock or #itsbrunchoklock.