Description
These thick, chewy bars pack in rolled oats, creamy peanut butter, rainbow candies, chocolate chips, and crunchy nuts—just like a classic monster cookie—but in an easy pan-baked format. Perfect for bake sales, lunchboxes, or an after-school treat, they vanish the minute they cool.
Ingredients
Dry Mix
-
1 cup (120 g) old-fashioned rolled oats
-
1 cup (130 g) all-purpose flour
-
½ tsp baking powder
-
½ tsp baking soda
-
¼ tsp salt
Wet Mix & Base
-
½ cup (115 g) unsalted butter, softened
-
½ cup (120 g) creamy peanut butter
-
½ cup (100 g) light brown sugar, packed
-
¼ cup (50 g) granulated sugar
-
1 large egg, room temperature
-
1 tsp vanilla extract
The “Monsters”
-
¾ cup (135 g) semi-sweet chocolate chips
-
½ cup (75 g) rainbow candy-coated chocolates (M&Ms)
-
½ cup (60 g) chopped pecans or peanuts
-
¼ cup (30 g) mini butterscotch or peanut-butter chips (optional)
Instructions
-
Prep: Preheat oven to 350 °F (175 °C). Line an 8×8″ (20×20 cm) pan with parchment paper, leaving an overhang for easy lifting; lightly grease.
-
Combine dry ingredients: In a medium bowl, whisk oats, flour, baking powder, baking soda, and salt; set aside.
-
Cream butter & sugars: In a large bowl, beat softened butter, peanut butter, brown sugar, and granulated sugar on medium speed until light and fluffy, about 2–3 minutes.
-
Add egg & vanilla: Beat in the egg and vanilla until fully incorporated, scraping down sides as needed.
-
Mix in dry ingredients: On low speed, gradually add the oat-flour mixture, mixing just until no streaks remain.
-
Fold in mix-ins: Using a spatula, gently fold in chocolate chips, candy-coated chocolates, nuts, and any optional chips until evenly distributed.
-
Press into pan: Transfer dough to prepared pan. Use a piece of parchment or lightly greased hands to press into an even, smooth layer.
-
Bake: Bake 20–24 minutes, until edges are golden and center is set but still slightly soft. Avoid overbaking.
-
Cool completely: Let the bars cool in the pan on a wire rack for at least 1 hour. Use the parchment overhang to lift the slab from the pan.
-
Slice & serve: Cut into 16 bars (4×4 grid) or 12 larger bars (3×4). Store airtight at room temperature up to 4 days.
Notes
-
Peanut-free: Swap peanut butter for sunflower-seed butter and omit peanut chips.
-
Oat texture: Use quick oats for a softer chew; old-fashioned for more bite.
-
Extra drizzle: Warm 2 Tbsp peanut butter + 1 Tbsp honey; drizzle over cooled bars.
-
Freezer-friendly: Individually wrap bars and freeze up to 2 months; thaw at room temperature.
-
Mix-in ideas: Dried cranberries, coconut flakes, pumpkin seeds, or chopped pretzels all work.
- Prep Time: 15 min
- Cook Time: 20 min