In a stand mixer or large bowl, beat together the softened unsalted butter, granulated sugar, and light brown sugar until light and fluffy.

Add in the eggs and vanilla extract, mixing until fully combined.

In a separate bowl, whisk together the flour, cocoa powder, baking soda, baking powder, and kosher salt.

Gradually fold the dry ingredients into the wet mixture until combined.

Cover the dough with plastic wrap and chill in the fridge for at least one hour.

Preheat your oven to 350°F (175°C) and line baking sheets with parchment paper.

Scoop and roll the chilled dough into balls and place on the prepared baking sheets with a 2-inch gap.

Bake for 8-10 minutes until the edges are set. Let the cookies cool completely.

In a bowl, beat together creamy peanut butter and softened butter until smooth.

Gradually add in the confectioners' sugar until the mixture is fluffy.

Spoon a dollop of the peanut butter mixture onto each cooled cookie and press down gently.

Melt together the chocolate chips and butter in a heat-safe bowl over simmering water.

Stir until smooth, then spoon the ganache over each cookie.

Allow the ganache to set at room temperature or chill briefly.