Chocolate Sandwich Cookies

Preheat oven to 375 degrees F. Line a baking sheet with parchment paper.

Place the flour, cocoa, baking soda, baking powder, salt, and sugar in a food processor bowl or mixer bowl. Stir or pulse to combine well. Pulsing the food processor, or on a low speed in the mixer, add the butter and egg until the dough comes together in a soft mass.

Wrap the dough in plastic and chill for 15 minutes.

Take rounded spoonfuls of dough and roll them into balls using the palm of your hands. Place them 1 1/2 inches apart on the parchment paper. Bake for 9 minutes. Cool baking sheets on a wire rack.

To make the filling: Combine all ingredients for the filling with a wooden spoon.

To assemble: Place 1/4- to 3/4-teaspoon-sized dollop of filling in the middle of one cookie and gently place another on top. Press to spread the filling toward the edges. Repeat for all cookies.