This quick and easy Chocolate Cookie Bar Recipe yields soft, chewy, and deeply chocolatey bars that are perfect for birthdays, bake sales, or any gathering. A chocolate sugar cookie base is baked in a sheet pan and finished with a creamy vanilla buttercream for an irresistible treat.
For the best flavor, use a high-quality cocoa powder in the dough. These bars also welcome mix-ins — stir in chocolate chips, chopped nuts, or swirl in peanut butter or caramel before baking to customize the flavor.
Chocolate Cookie Bar Recipe
Cookie bars are my go-to when baking for a crowd because they’re easy to portion and frost. These chocolate cookie bars bake in a 9″ x 13″ pan, are topped with homemade vanilla buttercream, and are cut into squares—no individual decorating required.
The dough is adapted from a classic sugar cookie recipe with the addition of cocoa powder. You can switch the frosting to chocolate buttercream or mint cream cheese frosting if you prefer, and a scoop of vanilla ice cream makes a lovely serving suggestion.
Key Ingredients
- Flour – all-purpose flour gives the right structure for these bars.
- Baking Soda – helps keep the texture soft and allows a slight rise.
- Cocoa Powder – use a good-quality cocoa for best chocolate flavor.
- Butter – use room-temperature butter; if needed, soften briefly in the microwave in short bursts so it doesn’t melt.
- Sugar – granulated sugar is used here; you can replace part with brown sugar for a chewier texture.
- Eggs – room-temperature eggs blend more smoothly with the butter.
How to Make Chocolate Cookie Bars
- Make the chocolate sugar cookie dough. In a stand mixer fitted with the paddle attachment, cream the butter, sugar, and vanilla until light and fluffy, about 3 minutes. Add the eggs one at a time, scraping down the bowl as needed. In a separate bowl whisk together the flour, cocoa powder, baking soda, and salt. Add the dry ingredients to the butter mixture and beat on low until combined; stop when no streaks of butter remain to avoid overmixing.
- Press the dough into a baking pan. Line a 9″ x 13″ baking pan with parchment paper or lightly spray with nonstick spray. Press the dough evenly into the bottom of the pan.
- Bake the cookie bars. Bake at 325°F for 20–25 minutes, or until the edges are set and the top is just beginning to turn golden. Remove from the oven and allow the bars to cool completely in the pan.
- Make the buttercream frosting. While the bars cool, make the frosting. Cream room-temperature butter in a stand mixer until light and fluffy. Add milk and powdered sugar and mix on low until incorporated. Add vanilla and mix again on low, then increase the speed and beat until the frosting is fluffy and spreadable. Add more powdered sugar if needed to reach the desired consistency.
- Frost and serve. Spread an even layer of buttercream over the cooled bars using an offset spatula. Add sprinkles if desired, then cut into about 20 squares. Serve and enjoy.
Frequently Asked Questions
A 9″ x 13″ pan is recommended for these bars. Use an 8″ or 9″ square pan for thicker bars, or a larger sheet pan (13″ x 17″) for thinner bars.
Because these bars are topped with buttercream, they should be stored in the refrigerator. Unfrosted bars can be kept at room temperature, wrapped or in an airtight container, for up to 3 days.
Yes. You can make them a day ahead and store in an airtight container in the fridge. You can also press the dough into a pan, wrap tightly, and freeze for up to 1 month; thaw and bake when ready.
Storing and Freezing
- Refrigerator: Store frosted cookie bars in an airtight container in the fridge for up to 1 week.
- Freezer: Frosted bars can be frozen for up to 1 month. Unfrosted bars freeze well for up to 2 months; thaw before frosting or serving.
Chocolate Cookie Bars Recipe
Ingredients
Chocolate Cookie Bars
- 1 cup butter, room temperature
- 1½ cups sugar
- 1 teaspoon vanilla extract
- 2 cups all-purpose flour
- 1/4 cup cocoa powder
- 1 teaspoon baking soda
- 1 teaspoon salt
- 2 large eggs
Buttercream Frosting
- 8 ounces butter, room temperature
- 3 cups powdered sugar
- 2 tablespoons milk
- 2 teaspoons vanilla extract
Instructions
Chocolate Cookie Bars
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Preheat oven to 325°F (163°C).
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Cream butter, sugar, and vanilla until light and fluffy, about 3 minutes. Add eggs one at a time, scraping the bowl as needed.
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Whisk together flour, cocoa, baking soda, and salt. Add to the wet ingredients and beat on low until combined.
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Line a 9″ x 13″ pan with parchment or spray with nonstick spray. Press dough evenly into the pan.
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Bake 20–25 minutes until set and lightly golden. Cool completely before frosting.
Vanilla Buttercream Frosting
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Cream room-temperature butter until light and fluffy.
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Add milk and powdered sugar on low until incorporated. Add vanilla, then beat on higher speed until fluffy and spreadable.
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Spread frosting over cooled bars, garnish as desired, and cut into 20 squares. Enjoy!
Notes
Nutrition
Disclaimer: Nutritional values are estimates provided for reference only.
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More Of the Best Cookie Bar Recipes
- Christmas Sugar Cookie Bars
- Coconut Cookie Bars
- Gingerbread Cookie Bars
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- Butterscotch Bars
- Orange Creamsicle Cookie Bars
- Lemon Sugar Cookie Bars
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These soft and chewy Chocolate Sugar Cookie Bars are finished with homemade vanilla buttercream and are ideal for serving at parties, bake sales, or any casual get-together.