This cake has everything you love about Monster Cookies – creamy peanut butter, soft oatmeal, mini chocolate chips, mini M&M’s, and it’s all wrapped up into a gorgeous cake that will have you thinking about your next slice the second you finish licking your plate.

This cake is just so much fun. I mean, look at that beauty!! It’s bright, it’s cheerful, and it has a little something for your inner cookie-dough-loving child,too. 🙂 It was such a joy to create, and even more of a delight to dive into.

If you’ve never heard of a Monster Cookie, or Monster Bars, or Monster anything, usually it’s referring to a dessert that has so many different components that traditionally include oatmeal, peanut butter, and a few toss-ins for fun. I wanted to create a cake that echoed all those familiar Monster Cookie flavors, and that meant oatmeal, peanut butter, M&M’s, chocolate, and of course COOKIE DOUGH!

I’ve included cookie dough in a couple of my different cakes – my most well known and loved is from my Funfetti Cookie Dough Cake from my best selling cookbook, Cake Confidence , and before I receive comments about the dangers of raw cookie dough – GOOD NEWS! The cookie dough is completely eggless, and you’re always welcome to pre-bake your flour as a precaution. Personally, I’ve never pre-baked my flour and have never had any problems, so it’s totally up to you.

I was going to incorporate the cookie dough between the layers like I’ve done in the past, but this time, I used my cookie scoop and scooped giant cookie dough balls on top of my cake. It’s quite the statement, and is a fun little topper to really make this cake something special. I’ve included instructions on how to add it between the layers if you’d like to add the cookie dough that way. I thought there was a lot going on inside the cake, so I left them on the top. And of course, snacked on the extra cookie dough this recipe makes. Not always a bad thing to have extra cookie dough, right? 😉

I knew I needed to have oatmeal in this recipe somewhere, but wasn’t quite sure how to incorporate it into the cake batter at first. Using raw old fashioned oatmeal was going to be a no-go because I wasn’t positive how the oatmeal would bake up inside my batter. Instead, I decided to just make my oatmeal separately over the stovetop, and then add that prepared oatmeal into my cake batter. It melded in perfectly, and gave the cake batter a really soft and gorgeous texture. It’s different than regular cake texture, but I love how it turned out. It really compliments the whole Monster Cookie scheme in a subtle, but effective way.

If you’re going to make any of my recipes that include peanut butter, go for the Skippy Peanut Butter (Creamy, not crunchy). I’ve used it for several years in my baking, and the flavor really can’t be beat. I know, I know, it’s not the healthiest, but LOOK AT THE CAKE YOU’RE MAKING, right? Dive into the dessert head first. I save my all-natural healthy PB for our sandwiches, haha.

Same goes for my peanut butter buttercream – this has been a favorite for not only us, but YOU! Thank you for making it over and over again. I knew it had to be a part of this cake because of you fine people. Same Skippy rule for this recipe, too. Trust me. You’ll want to spread this buttercream on everything.

When stirring in the mini M&M’s be careful – I noticed that they like to lend their color to anything they touch. Yep, you don’t want rainbow soup, so when you add them in at the very end, gently stir them in. Very gently.

The chocolate ganache is not only for show, but for a little extra chocolate taste. Feel free to add a layer between the cake layers, too, if you’d like. I used Wilton cocoa candy melts. So if you end up using chocolate chips, you’ll need to add in more heavy cream than this recipe calls for. The ratio of heavy cream to chocolate changes with which type of chocolate you use. It’s very forgiving, so if you find it too thin, add more chips. Too thick? Add in more heavy cream.

Hope you guys enjoy this one, I know so many of you have been waiting since I teased it on Instagram a few weeks ago. TIME TO DIVE IN, FRIENDS! I know we did!!!

As always, make sure to tag me on Instagram @bakingwithblondie so I can see all the baking fun.

xo, Mandy

Here’s a little video showing the process:

Monster Cookie Cake
Recipe Type: Cake
Author: Mandy Merriman
Oatmeal, Peanut Butter, Mini M&M candies, chocolate chips, and cookie dough… this cake HAS IT ALL when it comes to the popular Monster Cookie signature flavors!
Ingredients
  • MONSTER COOKIE CAKE
  • 1/2 Cup Old Fashioned Oats
  • 1 1/2 Cup Water
  • 3 Whole Eggs, room temperature
  • 1/2 Cup Sour Cream
  • 1/4 Cup Skippy Peanut Butter
  • 1/3 Cup Vegetable Oil
  • 3/4 Cup Buttermilk
  • 1 Tablespoon Vanilla
  • 1/4 Cup Mini Chocolate Chips
  • 1/3 Cup Mini M&M’s
  • 1 “Butter Golden” Cake Mix (I prefer Duncan Hines, but any other brand should be comparable)
  • [br]
  • EGGLESS MONSTER COOKIE DOUGH
  • 1/2 Cup Butter, Slightly Softened
  • 1/2 Cup Sugar
  • 1/2 Cup Packed Light Brown Sugar
  • 2 Tablespoons Milk
  • 2 tablespoons Vanilla Extract
  • 1/4 teaspoon Salt
  • 1 Cup All-Purpose Flour (pre-bake the flour itself if you wish)
  • 3 Tablespoons Oatmeal
  • 1/2 Cup Mini Chocolate Chips
  • ½ Cup Mini M&Ms
  • [br]
  • PEANUT BUTTER BUTTERCREAM
  • 2 sticks unsalted butter (1 cup)
  • 2/3 Cup peanut butter (Skippy brand is what I always use)
  • 1 pinch of salt
  • 1 Tablespoon Vanilla
  • 1/4 Cup Heavy Cream
  • 5-6 Cups sifted Powdered Sugar
  • [br]
  • GANACHE DRIP
  • 1 Cup Chocolate Cocoa Candy Melts
  • 1/4 Cup Heavy Cream
  • [br]
  • GARNISHES
  • Mini M&Ms
  • Mini Chocolate Chips
Instructions
  1. FOR THE CAKE:
  2. Preheat oven to 325 degrees (convection bake). Prep 3 6″ cake rounds with a swipe of shortening and dust of flour. Set aside.
  3. In a small saucepan, stir together prepared oats and water and boil over medium heat until oatmeal has cooked through, about 5-10 minutes. Add oatmeal to a small glass bowl and let cool completely.
  4. In a medium bowl(no need for the stand mixer), whisk together the oatmeal, eggs, sour cream, peanut butter, vegetable oil, buttermilk, and vanilla until thoroughly combined.
  5. Sift in the cake mix, gently stir it to combine (don’t overmix). Gently stir in the chocolate chips. Then barely stir in the mini M&Ms (they like to smear/spread, so to keep the integrity of the cake color, gentle fold-in is key).
  6. Split batter evenly between prepared cake pans and bake for 30-35 minutes. Let cool in pans for 2 minutes then flip out onto a wire rack to cool to room temperature. Wrap in plastic wrap and freeze for at least a few hours-overnight before frosting. Cold cakes are easier to frost than room temp ones.
  7. FOR THE EGGLESS COOKIE DOUGH:
  8. In the bowl of a stand mixer fitted with the paddle attachment, cream together the butter and sugar(s).
  9. Scrape down the sides of the bowl and add in the milk, salt, and vanilla.
  10. Mix in the flour, raw oatmeal, chocolate chips, and mini M&Ms.
  11. Mix on medium speed until thoroughly combined. Scoop with a cookie scoop into cookie scoops and place on a cookie sheet. Cover with plastic wrap and set aside. (OPTIONAL: If you’d like to use it as a filling, press the cookie dough into 2 plastic covered cake pans and freeze for 10 minutes to achieve a cake layer shape).
  12. FOR THE BUTTERCREAM:
  13. In a stand mixer fitted with a paddle attachment, whip up the butter and peanut butter together until thoroughly combined. Add in salt and heavy cream. Scrape down the sides of the bowl.
  14. Add in powdered sugar 1/2 cup at a time, then whip on high speed for 2 minutes until texture and color are lighter. Add in more heavy cream if needed.
  15. FOR THE GANACHE:
  16. In a small glass bowl, microwave chocolate pieces and heavy cream for 30 seconds. Stir until smoothe and add to squeeze bottle for ganache drips.
  17. ASSEMBLY:
  18. Place down first cake round on cardboard round with a touch of buttercream on the bottom to act as glue. Add on a layer of buttercream, then stack the next cake layer. Repeat with final cake layer.
  19. Crumb coat. Freeze for 2 minutes, then add on final layer of buttercream. Press mini chips and candies into the bottom rim of the cake (cookie sheet underneath keeps things less messy). Freeze for 2 minutes to set.
  20. Add on ganache drip, freeze for 1 minute to set, then add on cookie dough scoops and more candies/chips.
  21. Enjoy!