Preparation Steps

• Preheat your oven to 350°F (175°C). In a bowl, mix together the flour, cocoa powder, baking soda, and salt. Set this dry mixture aside for later.
• In another bowl, beat the softened butter, granulated sugar, and brown sugar together until smooth and creamy. Then, add in the egg and vanilla extract, continuing to mix until everything is well combined.
• Gradually add the dry ingredients to the wet mixture, stirring until just incorporated. You should have a nice, thick dough at this point.
• Scoop tablespoon-sized balls of dough onto a baking sheet lined with parchment paper, spacing them a few inches apart. Bake for about 10 minutes or until the edges are set.
• Let the cookies cool for a few minutes on the baking sheet before transferring them to a wire rack to cool completely.
• While the cookies are cooling, prepare the peanut butter filling by mixing the peanut butter and powdered sugar together until smooth.
• Once the cookies are completely cool, spread a generous amount of the peanut butter filling on the flat side of one cookie and then top it with another cookie, flat side down, to make a sandwich.
• Repeat this process until all cookies have been filled. Enjoy your delicious treats!