In a medium bowl, mix together flour, cocoa powder, baking soda, baking powder, and salt, and set aside
1 cup all-purpose flour, 1/4 cup cocoa powder, 1/2 teaspoon baking soda, 1/2 teaspoon baking powder, 1/4 teaspoon fine sea salt
In a large bowl, cream together butter, brown sugar, granulated sugar, peanut butter, and melted chocolate.
8 tablespoons unsalted butter, 1/2 cup packed brown sugar, 1/2 cup granulated sugar, 1/2 cup creamy peanut butter, 2 ounces unsweetened chocolate
Beat in egg and vanilla until smooth. Stir in flour mixture in batches, mixing until completely incorporated.
1 teaspoon pure vanilla extract, 1 large egg
Refrigerate dough for 20 minutes. Meanwhile, preheat oven to 350°F and line baking sheets with parchment paper or silicone liners.
Place the granulated sugar and powdered sugar into two separate shallow bowls. Form dough into balls, then roll each ball in granulated sugar, followed by the powdered sugar.
1/3 cup granulated sugar, 3/4 cup powdered sugar
Bake for 10-12 minutes. Let cool slightly on the baking sheet before removing to a wire rack.
Notes
Makes about 30 cookies using a 1 ½-inch cookie scoop.