Description
Deliciously chewy Triple Peanut Butter Monster Cookie Bars packed with creamy peanut butter, old-fashioned and quick oats, Reese’s Pieces, and peanut butter chips. These bars offer a perfect balance of sweet, nutty flavors and a delightful chewy texture, baked to golden perfection and ideal for sharing or snacking.
Ingredients
Wet Ingredients
- 1/2 cup (1 stick) salted butter, softened
- 1½ cups creamy peanut butter
- 3 large eggs
- 1 tablespoon vanilla extract
Dry Ingredients
- 1 cup light brown sugar
- 1 cup granulated sugar
- 3 cups old-fashioned oats
- 1½ cups quick oats
- 1 teaspoon baking soda
Add-ins
- 1 bag (9.9 oz) Reese’s Pieces (or Mini Reese’s Pieces)
- 1 cup peanut butter chips
Instructions
- Preheat and prepare pan: Heat the oven to 350° F. Prepare a 12″ x 18″ cookie sheet by spraying it with cooking spray or lining it with parchment paper. Set aside. Using parchment helps cook the bars evenly and prevents the bottoms from over-browning.
- Cream butter and peanut butter: In a large mixing bowl using an electric mixer or stand mixer with paddle attachment, beat the softened butter, creamy peanut butter, light brown sugar, and granulated sugar on medium speed until well combined, creamy, and fluffy, about 2-3 minutes. The mixture should be pale in color.
- Add eggs and vanilla: Add the eggs and vanilla extract to the creamed mixture and beat on medium speed until fully combined.
- Incorporate oats and baking soda: Add the old-fashioned oats, quick oats, and baking soda. Beat the mixture until thoroughly combined.
- Mix in Reese’s Pieces and peanut butter chips: Add the Reese’s Pieces and peanut butter chips. Beat until well distributed in the cookie dough. Optionally, reserve some pieces to press on top before baking for a decorative finish.
- Spread dough: Transfer the dough to the prepared cookie sheet and spread evenly using clean hands, a wooden spoon, or a spatula. Press reserved Reese’s Pieces and peanut butter chips on top if desired.
- Bake: Bake in the preheated oven for 16-20 minutes. The edges should turn lightly golden brown while the center remains slightly pale and underdone. Do not overbake, as bars continue to set while cooling.
- Cool: Remove the cookie sheet from the oven and let the bars cool at room temperature for 30 minutes to 1 hour. This cooling period allows them to firm up and finish cooking gently.
- Cut and serve: Cut the bars into squares using a pizza cutter for easy slicing. Serve warm or cooled to room temperature and enjoy!
Notes
- Use parchment paper to ensure even baking and prevent over-browning on the bottom.
- Beating the butter and sugars for at least 2 minutes is essential for a fluffy, pale mixture that contributes to the texture.
- Do not overbake; removing when the middle looks slightly underdone ensures chewy bars.
- These bars can be stored in an airtight container at room temperature for several days.
- Using a pizza cutter makes slicing these bars quick and clean.
- Prep Time: 15 minutes
- Cook Time: 20 minutes
- Category: Dessert
- Method: Baking
- Cuisine: American
