The only thing better than chocolate and peanut butter? Double chocolate and peanut butter!
Preheat oven to 325 F. Line a baking sheet with parchment paper and set aside.
In a medium bowl, whisk together flour, cocoa powder, baking soda and salt. Set aside.
In the bowl of a stand mixer (or using a hand mixer), beat butter and sugar until light and fluffy, about 2 minutes. Add egg and vanilla and mix until combined.
Add dry ingredients to bowl of wet ingredient and mix just until combined. Add Lily’s Semisweet Baking Chips and chopped Lily’s Peanut Butter Cups. Mix until incorporated (avoid over-mixing the dough).
Use a medium cookie scoop to scoop a mound of dough onto the baking sheet. Bake cookies for 10 minutes or until the edges are set. Allow the cookies to cool on the cookie sheet for 5 minutes before transferring to a wire cooling rack to cool completely.