Double Chocolate Chip Cookie Bars

With these double chocolate chip cookie bars, I set out to make a bar cookie that hits all the right notes: chewy, dense, chocolatey, and most of all, easy. Made in one bowl with melted butter and oil, these rich treats come together quickly, bake in 20 minutes, and slice perfectly once cooled.

Course Dessert, Snack

Cuisine American

Prep Time 20

Cook Time 20

Total Time 40

Servings squares (8 inch / 20 cm square pan)

Author Kathleen Culver

Equipment

8 x 8 inch square baking pan metal

Ingredients

113 grams unsalted butter
150 grams brown sugar light
25 grams granulated sugar
2 large egg yolks
7.5 mL vanilla extract
¾ teaspoon kosher salt Diamond Crystal
135 grams all purpose flour
25 grams cocoa powder Dutch or natural, sifted
½ teaspoon espresso powder optional, enhances chocolate depth
85 grams chocolate chips semisweet

Metric - US

Instructions

Place rack in center of oven and preheat to 350° Fahrenheit (177° Celsius, Gas mark 4)
Line an 8-inch (20 cm) square metal baking pan with parchment paper, leaving an overhang on two sides for easy removal.
Melt the butter in a microwave-safe bowl or small saucepan. Add both sugars and whisk until smooth and glossy.
113 grams unsalted butter, 150 grams brown sugar, 25 grams granulated sugar
Add egg yolks, vanilla, and salt. Whisk until fully combined.
2 large egg yolks, 7.5 mL vanilla extract, ¾ teaspoon kosher salt
In a separate bowl, sift together the flour, cocoa powder, and espresso powder (if using).
135 grams all purpose flour, ½ teaspoon espresso powder, 25 grams cocoa powder
Stir dry ingredients into wet until just combined. Fold in the chocolate chips or chunks.
85 grams chocolate chips
If your dough is still warm, it will most likely be pourable. If so, pour it into the pan and spread evenly.
If it has cooled and become thicker, scoop it into the pan in spoonfuls and press it into an even layer.
Bake for 20-22 minutes. The edges should be set, the top shiny, and the center should not jiggle.
Cool completely in the pan on a wire rack. Use the parchment overhang to lift out cooled bars and slice into squares.

Notes

Eggs - Using only egg yolks gives these bars a chewy, tender texture without any cakiness. If you prefer a more cake-like bar, use one whole egg plus one egg yolk instead.

Cocoa powder - Dutch or natural cocoa can be used interchangeably here. Since there is no leavening, either work without affecting texture.

Dough consistency

If you make the dough quickly, the melted butter will still be warm, and the dough will have a thinner consistency that can be poured into the pan.
If you make the dough slowly (or melt the butter over low heat), the dough will cool and firm up. You'll need to scoop and press it into the pan.
I baked batches with both dough consistencies with no noticeable change to the final results.

Slicing - For best results (and clean slices), wait until the bars are fully cooled before cutting into pieces and serving.

Pan size - Easily double the recipe using a 9 x 13 pan. You'll likely need to add a few extra minutes of bake time.

For ice cream sandwiches - If using these bars for ice cream sandwiches, consider omitting the chocolate chips. Regular chocolate chips (like Nestlé semi-sweet) become quite firm when frozen. Alternatively, replace the chocolate chips with finely chopped bar chocolate, which isn't as firm when frozen.

Storage - Store bars in an airtight container at room temperature for 3-4 days. Freeze in an airtight container or zipper sealed bag for 1-2 months.