Description
Warm, chewy, and rich with nostalgic cafeteria vibes, these peanut butter cookie bars bake in one sheet pan and get finished with a fudgy peanut butter frosting. Simple pantry staples, big payoff.
Ingredients
Units
Scale
Bars
- 1 1/2 cups creamy peanut butter (divided use)
- 3 sticks unsalted butter (melted)
- 2 cups granulated sugar
- 2 large eggs (room temperature)
- 1/2 cup milk
- 1 tsp pure vanilla extract
- 2 cups all-purpose flour (spooned & leveled)
- 1 tsp baking soda
- 1 tsp fine salt
Frosting
- 1 1/2 cups powdered sugar (sifted; more as needed)
- 2 Tbsp creamy peanut butter
- 3 Tbsp milk (plus more as needed)
- 1/2 tsp pure vanilla extract
Instructions
- Preheat & pan. Heat oven to 375°F (190°C). Grease a 10×15-inch rimmed sheet pan (jelly roll pan).
- Melt butter & peanut butter. In a saucepan (low heat) or microwave-safe bowl, melt 3 sticks butter with 1½ cups peanut butter, stirring until smooth.
- Make wet base. Off heat, stir in sugar. Whisk in eggs, milk, and vanilla until glossy. (Work briskly so the warm mixture doesn’t scramble the eggs.)
- Add dry ingredients. Fold in flour, baking soda, and salt just until no dry streaks remain—do not overmix.
- Bake. Spread batter evenly in prepared pan. Bake 15–18 minutes until edges are lightly golden and center is just set. Do not overbake.
- Frosting. Whisk powdered sugar, 2 Tbsp peanut butter, milk, and vanilla until smooth and pourable (adjust sugar/milk as needed).
- Frost & set. Spread frosting over warm bars so it melts slightly and bonds. Cool at least 20 minutes, then slice into 24 squares.
Notes
For clean cuts, chill 20–30 minutes before slicing. Add 1 cup quick oats to batter for an old-school cafeteria variation. Store covered at room temp 2 days or refrigerate up to 5 days.
- Prep Time: 15 minutes
- Cook Time: 18 minutes
- Category: Bars, Dessert
- Cuisine: American
Nutrition
- Calories: 320
- Sugar: 24
- Sodium: 200
- Fat: 18
- Saturated Fat: 9
- Carbohydrates: 36
- Fiber: 1
- Protein: 5
- Cholesterol: 45
