Description
Chewy, peanut buttery, and packed with chocolate—these Monster Cookie Bars are the perfect bake-sale, lunchbox, or weekend treat. No chilling, no scooping—just mix, press, and bake.
Ingredients
Scale
- 160 g (1 ⅓ cups) all-purpose flour
- 1 teaspoon cornstarch
- ½ teaspoon baking powder
- ½ teaspoon baking soda
- ½ teaspoon kosher salt
- 113 g (8 tbsp) unsalted butter, cold & cubed
- 135 g (½ cup) peanut butter, thick & creamy
- 160 g (¾ cup) dark brown sugar
- 50 g (¼ cup) granulated sugar
- 1 egg
- 1 egg yolk
- 1 teaspoon vanilla extract
- 68 g (¾ cup) old-fashioned rolled oats
- 100 g (½ cup) Reese’s pieces
- 85 g (3 oz) chocolate chips
- Candy eyes, for topping
Instructions
- Preheat oven to 350°F (175°C) and line a 9-inch square baking pan with parchment paper, leaving overhang.
- In a bowl, whisk together flour, cornstarch, baking powder, baking soda, and salt.
- In a stand mixer with paddle attachment, beat butter and peanut butter until smooth, 2–3 minutes.
- Add brown sugar and granulated sugar. Beat until light and fluffy, another 2–3 minutes.
- Mix in the egg, yolk, and vanilla until well combined.
- On low speed, add dry ingredients and mix just until incorporated.
- Fold in oats, Reese’s pieces, and chocolate chips with a spatula.
- Press dough evenly into prepared pan. Sprinkle extra mix-ins on top.
- Bake for about 22 minutes, until edges are golden and center looks slightly underdone.
- Cool completely in pan before lifting out. Cut into 16 squares and top with candy eyes if desired.
Notes
For a 9×13 pan, double the recipe and bake for 25–28 minutes. Store at room temperature for 4 days or freeze up to 3 months.
- Prep Time: 15 minutes
- Cook Time: 22 minutes
- Category: Dessert
- Method: Baking
- Cuisine: American
Nutrition
- Serving Size: 1 bar
- Calories: 230
- Sugar: 18g
- Sodium: 150mg
- Fat: 11g
- Saturated Fat: 5g
- Unsaturated Fat: 4g
- Trans Fat: 0g
- Carbohydrates: 28g
- Fiber: 1g
- Protein: 4g
- Cholesterol: 30mg