To make cookies:

1. Preheat oven to 350 degrees. Line baking sheets with parchment paper
2. Whisk together egg, maple syrup, butter & vanilla extract
3. In a separate large bowl combine the almond flour, cocoa powder, salt and baking soda. Add wet ingredients to dry ingredients and combine, then fold in chopped peanut butter cups
4. Refrigerate dough for 20-30 minutes (so it’s easier to work with)
5. Roll dough into 16 balls and flatten slightly. Place on baking sheet
6. Bake for 8-9 minutes. Transfer to cooling rack and let cool completely

To make frosting filling:

1. Cream the butter and peanut butter using a hand or stand mixer, then beat in the powdered sugar. Continue beating until reaches smooth and creamy consistency

To assemble cookie sandwiches:

1. Spread 1-2 tablespoons filling on a cooled cookie, then top with another cookie
2. Enjoy immediately and keep stored in the refrigerator