Monster Cookie Brownie Bars

Monster Cookie Brownie Bars: Gooey brownies sandwiched between two layers of monster cookie make for a delicious and comforting dessert/snack. Easy and quick to make, you’ll have these bars in your mouth with little effort involved – total. win.

Monster Cookie Brownie Bars | Sempre Dolce

Hi! I’m back.

I must confess that when taking a break from the blog over the holidays (and a little beyond), I didn’t expect to be gone this long! But life gets busy sometimes, you know?

Actually, what happened was the holidays (= busy), preparing for vacation, vacation, and then after that it’s a bit hard to get back in the swing of things.

So here I am near the end of January (which also means the end of most resolutions, right? Or is that Febraury?) with some photos from our time in the Rocky Mountains and… these Monster Cookie Brownie Bars for you to try (like I said, resolutions end in January, right??).

Idaho Springs, Colorado | Sempre DolceGranby, Colorado | Sempre DolceGranby, Colorado | Sempre DolceGranby, Colorado | Sempre Dolce

My family stayed in a cabin situated on top of a quiet hill near the Winter Park area of Colorado which featured the most gorgeous views. All in all we had a pretty great time, although nothing compared to the time my niece’s had – it was so fun to watch them experience some firsts in winter activities. :)

The Perk Coffee Company Winter Park CO | Sempre DolceGranby, Colorado | Sempre DolceGranby, Colorado | Sempre Dolce

OK, so about these bars. These monster cookies have been a family favorite and one of my personal favorites period (thanks, Sally!). So why not combine them with another one of my favorite desserts?

These bars are easy to make and I don’t think I need to say much about the yum factor. I mean, monster cookies + gooey brownies just kind of speaks for itself.

Monster Cookie Brownie Bars | Sempre Dolce

This recipe is easy to put together as the cookies are a one bowl affair and you can use a box mix for the brownies. I don’t usually go in for boxed mixes, but we had one around the house that needed to be used and since the brownies were going to be sandwiched between peanut butter cookie goodness, I used it to make life easier. And really, in this case you couldn’t tell – #winwin. But feel free to make them from scratch too!  Either way, they’re going to be soo good.

Monster Cookie Brownie Bars | Sempre Dolce

Cottura Felice!

Monster Cookie Brownie Bars
Save RecipeSave Recipe


  • 3/4 C. (1 ½ sticks) unsalted butter, softened
  • 3/4 C. light brown sugar, packed
  • ¼ C. + 2 tbsp. granulated sugar
  • 1 C. + 2 tbsp. creamy peanut butter
  • 2 large eggs
  • 1 ½ tsp. vanilla extract
  • 3/4 tsp. baking soda
  • 1 ¾ C. + 2 tbsp. all-purpose flour
  • ¾ C. quick oats
  • 1 1/2 C. M&Ms
  • 3/4 C. semi-sweet chocolate chips
  • 1 box brownie mix (I used Ghiradelli’s Double Chocolate Brownie mix) or your favorite recipe (see note below!)


  1. Preheat oven to 350° F.
  2. Line a 9x13” baking dish with parchment paper, and spray with cooking spray.
  3. Set aside.
  4. In the bowl of a stand mixer fitted with the paddle attachment, or using a hand-held mixer and large mixing bowl, cream the butter and sugars together on medium speed until combined, about 2-3 minutes.
  5. Add peanut butter, eggs, and vanilla, mixing to combine and scraping down sides of bowl as needed.
  6. With the mixer on low speed, mix in baking soda and flour, mixing until just combined.
  7. With a rubber spatula, fold in quick oats, M&Ms, and chocolate chips.
  8. Set aside.
  9. Prepare brownie batter according to recipe directions.
  10. Press half of cookie dough evenly in the bottom of the pan.
  11. Pour brownie batter on top and then crumble remaining cookie dough evenly over brownie batter.
  12. Bake for 47-55 minutes, or until a toothpick comes out with moist crumbs when inserted. Cover the bars with foil if you notice the cookie top getting brown early (you might check around 30-40 min).
  13. Remove from oven and place on a cooling rack. Let cool almost completely before removing and serving.


Make sure the brownie recipe you use yields a 9x13" pan of brownies.

Monster Cookies adapted from Sally’s Baking Addiction




This site uses Akismet to reduce spam. Learn how your comment data is processed.