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Stuffed Cookie Bars are going to be your latest obsession. I’m 100% serious when I say that these are literally the best ultimate gooey bars – ever. These are my favorite cookies stuffed with tons of candy – and made into gooey bars. They’re EPIC!

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stacked gooey bars with M&Ms baked in

I’ll be the first to tell you that I can’t get enough of this candy bar stuffed cookie bars. They’re ooey, they’re gooey, and they’re oh so addictive. The first time that we made these peanut butter stuffed cookie bars, I knew that we’d hit gold. 

We love adding in extra peanut butter cups because why not? You can never have too many sweets and treats and candy bits combined with that delicious cookie flavor. 

Why you’ll love this recipe

laid out gooey bars with M&Ms baked in


We’re making TWO kinds of cookies PLUS a filling, so you’ll need a few ingredients and mixing bowls.

  • Unsalted butter – Melted for the chocolate chip cookies, softened for the oatmeal cookies.
  • Brown sugar – You can use light brown sugar. Be sure to pack it.
  • Granulated sugar – Added for the sweetness. 
  • Egg – Used as the binding agent for the dry ingredients. 
  • Vanilla extract – Pure vanilla extract is the best. 
  • Baking soda – Great for adding a chewy texture. 
  • Salt – Just a little bit! 
  • All-purpose flour – The main ingredient needed to make the cookie dough. 
  • Chocolate chips – Mini chocolate chips or regular ones work just fine. 
  • Sweetened condensed milk – Excellent for creating that gooey texture in the filling.
  • Peanut butter cups and M&Ms – The perfect candy bar additions!
  • Ground cinnamon – You could use pumpkin pie spice during the fall! 
  • Quick cooking oats – These are for the oatmeal cookies – make your own quick oats
  • Preheat. Preheat the oven to 350 degrees. Line a pan with foil and spray with nonstick spray.
  • Make chocolate chip cookies: Put the melted butter into a bowl. Add the sugars and stir until smooth, then mix in the egg and vanilla. Mix the baking soda and salt, then add the flower slowly. Fold in the chocolate chips. Press the batter into the pan. 
  • Add the topping. Pour the condensed milk over the top and leave a ½ inch border around the edges. Put the peanut butter cups on top. 
  • Make the Oatmeal Cookies: In a bowl, add the salt, cinnamon, baking soda, and flour. Set to the side. Cream butter and sugar with a stand mixer until smooth. Add the eggs and vanilla. Mix in the dry ingredients but don’t overmix. Add the oats and mix, then add the M&M’s. 
  • Add the dough. Drop spoonfuls of the dough over the top of the peanut butter cups in the pan and flatten. 
  • Bake. Put in the oven and bake for 30-38 minutes. Cool before cutting. 

Expert Tips

You’re going to have a blast changing up these bars! Add in Hershey’s candy bar bits, Reese’s Pieces, or even some sweetened shredded coconut as well.

stacked gooey bars with M&Ms baked in

Storing and Freezing Stuffed Cookie Bars

Since this recipe makes a large portion, you’re probably going to have some leftovers. Just let them cool down all the way and then add them to an airtight container. You can keep them at room temperature for up to 4 days.

You can also freeze stuffed cookie bars for up to 3 months. Learn to freeze dessert!


How do I know when these cookie bars are done baking? 

The top of the cookie bars shouldn’t have any gloss to them, indicating that they’re done baking. Look at the edges of the cookie bars as well, as they’ll be pulling away from the pan. 

Why are my cookie bars crumbly? 

If you overmix the cookie bars, there’s a chance that they’re going to be drier than normal. Just mix until combined and then bake. 

Can I add other toppings to these gooey cookie bars? 

You can! You can drizzle chocolate, caramel, or anything else that you’re craving. Have fun and make them unique! 

Have You Made This Recipe?

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stacked gooey bars with M&Ms baked in
5 from 3 votes
These amazing bars are the ultimate dessert. Stuffed with M&Ms and other candies!
Prep Time 1 hour
Cook Time 35 minutes
Total Time 1 hour 35 minutes
Yield 36 servings
Serving Size 1 serving


For the Chocolate Chip Layer:

  • ½ cup (113g) unsalted butter, melted
  • ½ cup (100g) packed brown sugar
  • cup (67g) granulated sugar
  • 1 large egg
  • 1 teaspoon vanilla extract
  • ½ teaspoon baking soda
  • ½ teaspoon salt
  • 1 ½ cups (186g) all-purpose flour
  • 1 ½ cups (255g) chocolate chips

For the Filling:

  • 1 14 ounce can sweetened condensed milk
  • 24 regular size peanut butter cups

For the Oatmeal Cookie Layer

  • ½ teaspoon ground cinnamon
  • ½ teaspoon salt
  • ½ teaspoon baking soda
  • ¾ cups (93g) all-purpose flour
  • ½ cup (113g) unsalted butter, softened
  • ¾ cups (150g) packed brown sugar
  • 1 large egg
  • ½ teaspoon vanilla extract
  • 1 ½ cups (138g) quick cooking oats
  • ¾ cup (160g) M&Ms


Make Chocolate Chip Cookies:

  • Preheat oven to 350°F. Line a 9×13-inch pan with foil and spray with nonstick cooking spray.
  • Place melted butter in a large bowl. (You can also use a stand mixer fitted with the paddle attachment or a hand mixer.) Add granulated and brown sugars and stir until the mixture is smooth. Stir in egg and vanilla extract and stir until combined.
  • Mix in baking soda and salt, then slowly mix in flour and mix just until the batter is smooth and comes together. Be sure to scrape the sides of the bowl during mixing. Slowly mix in chocolate chips.
  • Press batter in the bottom of prepared pan.
  • Spread sweetened condensed milk over the cookie dough, leaving a ½ inch border around the edges of the pan. Place peanut butter cups on top the milk.

Make Oatmeal Cookies:

  • In a medium bowl, whisk cinnamon, salt, baking soda, and flour. Set aside.
  • Cream butter and sugar in the bowl of a stand mixer fitted with the paddle attachment. (You can also use a large bowl and a hand mixer.) Cream until smooth, about 1-2 minutes. Mix in eggs and vanilla, beat until smooth.
  • Gradually mix in dry ingredients until smooth, being careful not to over mix. Add oats and mix, then stir in M&Ms.
  • Drop spoonfuls of the dough over the top of the peanut butter cups in prepared pan and lightly press to flatten and cover the top (some areas won’t be totally covered).
  • Bake 30-38 minutes, or until light golden and no longer glossy. Cool completely before slicing into bars. (It’s easiest to slice these when they are cold.)
  • Store in an airtight container for up to 4 days or freeze for up to 3 months.

Recipe Nutrition

Serving: 1serving | Calories: 314kcal | Carbohydrates: 45g | Protein: 5g | Fat: 13g | Saturated Fat: 7g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 3g | Trans Fat: 0.2g | Cholesterol: 26mg | Sodium: 153mg | Potassium: 106mg | Fiber: 2g | Sugar: 25g | Vitamin A: 217IU | Vitamin C: 0.1mg | Calcium: 43mg | Iron: 2mg
Nutritional information not guaranteed to be accurate
Course Dessert
Cuisine American
stacked gooey bars with M&Ms baked in with words on top

Stuffed Cookie Bars are the ultimate cookie bar recipe – these chocolate chip bars are stuffed with peanut butter cups!

Dorothy Kern

Welcome to Crazy for Crust, where I share recipes that are sometimes crazy, often with a crust, and always served with a slice of life.

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  1. I have sent you an inquiry about your estimate on the cost of this recipe, as well as another one both by leaving a comment and by sending an email. I have not received a response to either and I am curious as to why you would not respond.