Double Chocolate Cookie Bars

These easy double chocolate cookie bars are rich, thick, and soft – a true crowd favorite loaded with chocolate flavor! They are made in one bowl, no mixer required. The chocolate version of my Tiktok viral chocolate chip cookie bars!

Course Dessert

Cuisine Cookie

Keyword Chewy M&M Cookie Bars, double chocolate cookie bars

Prep Time 10

Cook Time 15

Total Time 25

Servings squares

Calories 196kcal

Author Melissa Rose

Ingredients

¾ cup unsalted butter (not margarine) You will be melting this
¾ cup light brown sugar
½ cup granulated sugar
1 large egg + 1 yolk (i.e. 1 whole egg + 1 extra egg yolk)
2 teaspoons vanilla extract
¾ teaspoon baking soda
¾ teaspoon salt
¾ cup unsweetened cocoa powder I use Hershey's
1 ½ cups all-purpose flour
1 ½ cups semi-sweet chocolate chips (divided, 1 ¼ cups in dough + ¼ cup sprinkled on top)

Optional Topping

Flaky sea salt optional

Instructions

Preheat oven to 350°F.
In a medium-sized microwave-safe bowl, melt unsalted butter (¾ cup, i.e. 1 ½ sticks) for 30-60 seconds until fully melted. If your butter is steaming, let it cool down for a few minutes. Butter that is too hot can result in greasy bars and/or will cause the eggs to cook.
Add in light brown sugar (¾ cup) and granulated sugar (½ cup) and use a spatula to stir until combined. Stir in 1 whole egg, 1 extra egg yolk and vanilla extract (2 teaspoons). Mix until combined.
Stir in baking soda (¾ teaspoon) and salt (¾ teaspoon).
Add in unsweetened cocoa powder (¾ cup) and all-purpose flour (1 ½ cups). Before all the flour disappears, add in 1 ¼ cups of chocolate chips. Mix until all the flour disappears into the dough. Immediately proceed to next step.
Press dough into a greased or parchment-lined metal 9x13" pan until smooth. Sprinkle the remaining ¼ cup chocolate chips on top and gently press each one into the dough.
Bake at 350°F for 14-16 minutes, or until center no longer looks wet. Do not overbake or the bars will not be soft & may taste bitter. Remove from oven and place entire pan on a cooling rack. If desired, sprinkle with flaky sea salt.
Allow the cookie bars to cool completely before removing from pan. Slice into 12-24 squares, then enjoy! To keep fresh, cover pan with saran wrap or place bars in airtight continer for up to 2-3 days (best within 2 days or they start to dry out). See notes below for freezing tips.

Video

Notes

Chocolate chips: While I use semi-sweet chocolate chips, you can also use milk, dark, or white chocolate!

To freeze: To freeze, cool the bars completely before placing them into an airtight container or freezer bag for storage. These will keep in freezer for 1-2 months. Note that I find that the freezer tends to dry out cocoa powder cookies quicker than other types, so texture will change as time goes on.

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