10tablespoons(5 ounces) unsalted butter, at room temperature
1large egg
For the peanut butter cookie dough filling:
4tablespoons(2 ounces) unsalted butter, at room temperature
1/2cupcreamy peanut butter
1/4cuplightly packed light brown sugar
2tablespoonsgranulated sugar
1/4cupmilk (any kind)
1/2teaspoonvanilla extract
1 1/4cupsall-purpose flour
1/8teaspoonfine salt
1/2cupminiature chocolate chips
Instructions
For the cookies:
Preheat the oven to 375°F. Line large baking sheets with parchment paper.
In the bowl of an electric mixer, combine the flour, cocoa, baking soda, baking powder, salt, and sugar. On low speed, add the butter then the egg. Continue mixing until the dough comes together.
Take rounded teaspoons of dough and place on prepared baking sheets, spacing about 2-inches apart. Use the bottom of a measuring cup or a glass to slightly flatten the dough. Bake for 9 minutes. Set on a cooling rack to cool completely.
For the filling:
In the bowl of an electric mixer, beat the butter and peanut butter on medium-high speed until light and creamy. Add the brown sugar and granulated sugar and beat until well combined. Add the milk and vanilla, beating until combined. On low speed gradually add the flour and salt, beating until just combined. Stir in the chocolate chips.
Dollop 1 tablespoon of filling onto the bottom of half of the cookies. Sandwich with the remaining cookies, pressing lightly. Serve or store in an airtight container in the fridge for up to 1 week. Serve at room temperature.