Peanutty Cookie Dough Brownies

For the brownies:
Preheat oven to 350ºF with a rack in the middle position. Line a 13×9 inch baking pan with foil, then grease and flour the foil.

In a small bowl, whisk together flour, baking powder, and salt. Set aside.

In a medium saucepan, melt the semisweet chocolate chips and unsweetened chocolate together with butter over medium-low heat, stirring frequently. When smooth, remove from heat and let cool for 20 minutes. Whisk in granulated sugar, then add the eggs one at a time, whisking thoroughly after each addition. Whisk in vanilla.

Add the dry ingredients and fold them in gently with a wooden spoon, just until the flour is incorporated. Fold in the peanuts. Pour the batter evenly into the prepared pan. Bake brownies for about 25 to 30 minutes, until just set and the top is dry. Cool brownies in pan on a wire rack completely. Freeze brownies for at least an hour before topping with cookie dough.

For the cookie dough:
In a large bowl, combine melted butter, granulated sugar, and brown sugar, stirring thoroughly with a rubber spatula. Stir in the milk and vanilla extract. Stir in salt, then flour. Fold in the mini chocolate chips. You can use the cookie dough immediately or cover it and refrigerate it until use. (You should let it soften at room temperature a bit before using if you chill it.)

To assemble the brownies:
Spread the peanut butter evenly over the chilled brownies. Press soft cookie dough evenly over the peanut butter, covering the whole surface of the brownies. I found it was easiest to flatten chunks of cookie dough in my hands, then press these dough pancakes onto the peanut butter. Then I went back with bits of dough to fill in the holes. Chill brownies in refrigerator for at least 30 minutes before slicing. Brownies will keep covered and chilled for up to 5 days; they can also be frozen for longer.

Recipe for brownies adapted from The Buttercup Bake Shop Cookbook; recipe for cookie dough adapted from America’s Test Kitchen’s Baking Illustrated.