Monster Cookie Bars nine squares

Monster Cookie Bars

Cookies Dessert

Monster Cookie Bars are loaded up with all the good stuff. Oats and chocolate and nuts and maybe more chocolate. They’re an indulgent way to use up extra candy in your cupboard.

Monster Cookie Bars nine squares

My observation is that British people seem to love candy, but they’re not that into Halloween. They’re constantly sharing around bags of bite-size chocolate and gummy candies of various shapes and sizes. There are at least two whole rows at my regular grocery store given over to candy. Of course, they would never call it candy. It’s sweets and chocolate, but that’s just semantics.

Given all this, you’d think they’d be super into Halloween and all the candy-eating that trick-or-treating, and let’s be honest, the lead up to trick-or-treating, promises. But you hardly see Halloween candy anywhere, and I don’t know if I’ve ever seen a trick-or-treater. Granted we live in an apartment and for some reason tend to always be travelling on Halloween. But all I’ve ever seen is drunken college students in revealing costumes. They don’t seem to take advantage of the sugary possibilities. I don’t quite get it.

Monster Cookie Bars with candy

Why should you make this recipe?

So I’m going to suggest you make Monster Cookie Bars any time you have extra chocolate candies lying around your house, be that Halloween or any other day. You can use any type of chocolate you like here. It’s pretty damn awesome no matter what you do.

For my Monster Cookie Bars this time, I used some chopped up macadamia nuts, salted caramel M&Ms, tiny Reese’s peanut butter cups, and something called crunchie rocks by Cadbury. That was Goeff’s pick. The point is, it doesn’t matter that much. I think it’s always a good idea to include M&Ms for color, but it’s totally up to you. Just make sure that if you’re using bars, even fun size, that you chop them up a bit for more even distribution.

Monster Cookie Bars in a stack

How to make Monster Cookie Bars

Making these bars is pretty easy. You just need to make a couple of components. One is the oatmeal cookie dough that’s going to form the base of our bars and give us so much texture. The next is a chocolate layer that goes in the middle and makes these ridiculously chocolatey. The final component is all your extra mix-ins that get scattered on top.

You’re going to press half of your oatmeal cookie dough into the bottom of your foil-lined pan, then pour over the melty chocolate mixture. Then we scatter on our candy bits. The only slightly tricky part is the top layer of dough. You can’t just spread it on, because it’s going onto a layer that’s basically liquid. I pinched off bits of the dough, flattened it out, and just spread it over the top trying to cover as much as possible. Don’t worry if it’s not completely covered. The bottom layer of dough will give you enough structure.

You also need to cool these completely before eating. I stored mine in the fridge as well. Not that they lasted long.

Monster Cookie Bars in a stack with a bite

No matter what the occasion, we all love chocolate. These Monster Cookie Bars are a super fun way to enjoy it. Get baking, kids. It’s gonna be awesome.

Looking for more awesome ways to use up extra chocolate? Try my Quarantine Cookies?


Monster Cookie Bars

Monster Cookie Bars in a stack with a bite

Monster Cookie Bars are loaded up with all the good stuff. Oats and chocolate and nuts and maybe more chocolate. They’re an indulgent way to use up extra candy in your cupboard.

  • Author: Renee Rendall
  • Prep Time: 20
  • Cook Time: 45
  • Total Time: 1 hour 5 minutes
  • Yield: 16 bars 1x
  • Category: Dessert
  • Method: Baked
  • Cuisine: American
  • Diet: Vegetarian


  • 4 ounces (1 stick) butter
  • 1 cup all purpose or plain flour
  • 1 cup quick cooking oats
  • 3/4 teaspoons baking powder
  • 1/4 teaspoon baking soda
  • 1/2 cup brown sugar
  • 1 eggs
  • 1/4 cup chocolate chips
  • 1/4 cup chopped macadamia nuts
  • 1/2 cup M&Ms, crushed, any variety
  • 1/2 cup milk
  • 7 ounces dark chocolate, chopped
  • 1/2 cup sweetened condensed milk
  • Mini Reese’s peanut butter cups (a handful)*
  • M&Ms (a handful)*
  • Any other chocolate bits (a handful)*


  1. Preheat oven to 350 C (175 F) and line an 8×8 pan with foil, allowing some to hand over the edge for easy removal.
  2. In a small sauce pan over medium heat, melt the butter and continue to cook until it turns lightly brown and begins to smell nutty. Allow to cool for about 10 minutes.
  3. In a small bowl, combine flour, oats, baking powder, and baking soda. Set aside.
  4. In a mixing bowl, beat together brown butter and brown sugar until combined. Add egg and beat for about 3 minutes.
  5. With the mixer on low, slowly incorporate the flour mixture, then add the chocolate chips, mac nuts, and crushed M&Ms.
  6. In a small sauce pan over low heat, combine the milk, chocolate, and condensed milk. Stir slowly until the chocolate is completely melted. Remove from heat.
  7. Press about half of your cookie dough in the bottom of the pan. Pour the melted chocolate over this, and sprinkle your peanut butter cups, M&Ms, and/or whatever other chocolate candy you like into the pool of chocolate. Then crumble the rest of the cookie dough over the top. Don’t worry about covering the whole thing completely.
  8. Bake for about 45 minutes. Cool completely before cutting. Store in an air-tight container, preferably in the fridge.


* You don’t need to use the same type of chocolate candies I used. Use what you have and/or what you love. Just scatter in however much you like to create a layer of candy chunks.

Keywords: Candy, Cookie Bar

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Recipe adapted from Bakers Royale.

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