Traditional monster cookies are oatmeal cookies with peanut butter, chocolate chips, and M&Ms. Take those same ingredients, remix them, and you’ve got the monster cookie’s funky younger sister. What you see here are soft peanut butter cookie bars, with lots of M&Ms®, and some chewy oats for texture. Instead of simply adding chocolate chips to the dough, I opted to melt them down into a fudge-like consistency to create a decadent ripple in the center. Try to resist sneaking a lick of the fudge ripple … I dare you!
Ingredients
Monster Bars
- 10.33 cups (170g) all-purpose flour
- 0.66 cup (60g) old-fashioned rolled oats
- ½ tsp baking soda
- ½ cup (1 stick or 115g) salted butter, softened to room temperature
- ½ cup (100g) light brown sugar
- ¼ cup (50g) granulated sugar
- ¾ cup (185g) creamy peanut butter
- 1 egg
- 1 tsp vanilla extract
- ¾ cup (150g) M&Ms
Fudge Ripple Filling
- 7 oz (200g or ½ x 14oz can) sweetened condensed milk
- 1 tbsp salted butter
- 1 cup (180g) semi-sweet chocolate chips
- 1 tsp vanilla extract
How to Make It
- Preheat the oven to 350°F. Line the bottom and sides of an 8 x 8in baking pan with aluminum foil, leaving an overhang on all sides. Set aside. Make The bars
- Whisk the flour, oats, and baking soda together in a large bowl. Set aside.
- Using a handheld or stand mixer fitted with a paddle attachment, beat the butter, brown sugar, and granulated sugar together in a large bowl on medium speed until creamed, about 2–3 minutes. Add the peanut butter, egg, and vanilla one after the other, mixing after each addition. Scrape down the sides of the bowl as needed. With the mixer running on low, slowly add the dry ingredients into the wet ingredients until combined. Do not overmix.
- Press two-thirds of the dough evenly into the prepared baking pan. Stir the M&Ms into the remaining dough. Set aside while you make the fudge ripple filling. Make The Fudge Ripple
- In a small saucepan over a low heat, combine the sweetened condensed milk, butter, and chocolate chips. Stir until the chocolate chips are melted and the mixture is smooth. Remove from the heat and stir in the vanilla. Pour the fudge over the bottom layer of dough.
- Mold the remaining dough containing M&Ms® into flat pieces and layer on top of the fudge filling. You won’t have enough dough to make one single layer, so some of the filling will be exposed.
- Bake for 25 minutes or until the top is lightly browned. Allow to cool completely. Lift the foil out of the pan using the overhang on the sides and cut into bars. Bars stay fresh in an airtight container at room temperature or in the refrigerator for up to 1 week.
