Peanut Butter Rocky Road Bars

If you love the classic combination of peanut butter and chocolate, you’re in for a treat with these peanut butter rocky road bars! They start with a soft and chewy peanut butter cookie base and are topped with melty chocolate, fluffy marshmallows, and crunchy nuts for a perfect balance of flavors and textures.

These bars are simple to make, with a quick mix-and-bake method that keeps things fuss-free. The peanut butter base bakes just enough to set before getting topped with the irresistible rocky road mix. A few more minutes in the oven, and everything melts together into gooey, chocolatey perfection!

Why You’ll Love These Peanut Butter Rocky Road Bars

• A fun twist on rocky road. Classic rocky road flavors meet a soft, peanut butter-infused base.
• Easy to make. No complicated steps or extra equipment needed!
• Perfect for sharing. These bars are rich and satisfying, making them great for potlucks, bake sales, or just a sweet treat at home.

What You’ll Need

• All-purpose flour – Measure by weight or use the spoon and level method for accuracy.
• Baking powder – Not sure if yours if still active? Test it!
• Salt – I usually bake with table salt. If you have a different kind on hand, you may want to make adjustments.
• Unsalted butter – Let this soften at room temperature before mixing.
• Granulated sugar and brown sugar – The combination provides not just sweetness but softness.
• Peanut butter – Creamy or crunchy both work, so use your favorite!
• Egg – Let this come to room temperature for easier mixing.
• Vanilla extract – I like to use my homemade vanilla extract, but store-bought is fine.
• Chocolate chips – The chocolatey layer in the rocky road topping.
• Mini marshmallows – Add a chewy, gooey touch.
• Chopped nuts – For crunch! Almonds are the traditional choice in rocky road desserts, but peanuts, pecans, or walnuts all work well. Use a combination if you like.

How to Make Peanut Butter Rocky Road Bars

• Prepare for baking. Heat the oven to 350°F and grease an 8-inch square baking pan. Line with parchment paper if you like.
• Mix dry ingredients. Combine flour, baking powder, and salt.
• Mix wet ingredients. Beat butter and both sugars until fluffy and lightened in color. Mix in the peanut butter, followed by the egg and vanilla.
• Combine wet and dry. Gradually mix the dry ingredients into the wet ingredients.

• Bake. Spread evenly in the pan and bake 20-25 minutes or until slightly underbaked. (This helps keep them soft after the second bake.)
• Add the topping. Mix the topping ingredients, sprinkle over the bars, and bake 5 more minutes.
• Cool. Let the bars cool before cutting and serving.

Variations

• Other nut butters: You can substitute peanut butter with almond butter, cashew butter, or sunflower seed butter for a different twist.
• Different nuts: I usually just grab whatever I happen to have on hand. Pecans, almonds, hazelnuts, macadamias… whatever you like! I recommend chopping them roughly so that you’ll get some large pieces to mix with the chocolate chips and marshmallows.
• White chocolate: Swap semisweet chocolate chips for white chocolate chips for a sweeter variation.
• Crunchy cookie base: Use crunchy peanut butter instead of creamy for extra texture.
• Extra chocolatey: Add an extra 1/2 cup of chocolate chips to the base for a richer flavor.
• Want even more peanut butter? Drizzle melted peanut butter over the top after baking!

How to Store

• Room temperature: These bars keep well at room temperature for 3–4 days in an airtight container.
• Refrigerator: If you prefer a firmer texture, store the bars in the refrigerator, but let them sit at room temperature for a few minutes before serving. 
• Freezer: These bars also freeze well for up to 3 months—just wrap them individually for easy grab-and-go treats! Thaw overnight in the refrigerator or for a couple of hours at room temperature.