Chewy Monster Cookie Bars with Oats and Peanut Butter

If you’re craving a sweet treat that’s both chewy and satisfying, these bars are just the thing. Packed with oats and peanut butter, they’re perfect for a quick snack or an anytime indulgence.

★★★★★5(1 reviews)Updated: Mar 31, 2026

Prep Time 10 min

Cook Time 13 min

Total Time 23 min

Difficulty Easy

Ingredients 0/9

Bars: 1 cup packed brown sugar ¼ cup light corn syrup ¼ cup peanut butter ½ teaspoon vanilla extract 4 cups quick-cooking oats Topping: 1 cup semisweet chocolate chips ½ cup butterscotch chips

Why You'll Love This Recipe

These bars are the perfect balance of chewy and crunchy, thanks to the oats and peanut butter. They offer a rich, nutty flavor with a satisfying texture that makes them a great treat any time of day. Plus, they’re easy to make and great for sharing.

Smart Cooking Tips

- Use natural peanut butter for a more authentic flavor.
- Don’t overmix the batter to keep the bars tender.
- Press the dough evenly in the pan to ensure uniform baking.

Step 1

Gently heat your oven to 400°F (200°C) and greasing a 9x13-inch baking pan. In a bowl, mix together the brown sugar, butter, corn syrup, 1/4 cup of peanut butter, and vanilla extract until everything is combined. Gradually stir in the oats until they’re fully coated. Press this mixture evenly into your prepared pan.

Step 2

Pop it in the oven and bake for about 12 to 14 minutes, or until the bars turn a nice golden brown. When they’re done, let them sit for about 4 minutes to cool slightly.

Step 3

While the bars are still warm, melt the chocolate chips, butterscotch chips, and the remaining 1/3 cup of peanut butter together. I like to do this in the microwave in 15-second bursts, stirring in between until smooth and well blended. Spread this gooey topping over the bars.

Step 4

Let everything cool completely for a couple of hours before slicing so the topping sets up nicely. Enjoy!

Best Pairings For This Dish

Enjoy these bars warm with a glass of cold milk or a cup of coffee. They also pair well with a scoop of vanilla ice cream for a simple dessert. Cut into small squares for lunchbox snacks or parties.

How To Freeze This Dish

Store the bars in an airtight container at room temperature for up to a week. For longer storage, keep them in the fridge or freeze them wrapped tightly for up to three months. Let frozen bars thaw before eating for the best texture.

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By Ayesha Khan

Home Cooking Expert

Ayesha shares simple recipes with clear steps to help you cook confidently at home.