Preheat your oven to 350 degrees F and line an 8x8-inch square baking pan with parchment paper.

Place butter, sugar, salt, baking powder, spices, molasses, and vanilla in a large mixing bowl. Beat until creamy. Beat in eggs, one at a time, until well incorporated. Beat in flour until evenly mixed. Divide dough in half, leaving one half in the bowl. Take the other half and spread or press it evenly into your prepared pan.

To the half that was left in the bowl, beat in cocoa powder and melted warm chocolate until evenly incorporated. Scatter portions of this dough over the gingerbread dough in the pan and then press it down evenly. Bake at 350°F for 25 minutes. Let cool for 20 minutes.

Carefully remove the cookies from the baking sheet and cut into ¾″ slices. Lower the heat of the oven to 300°F. Place the cookies so they are flat on the baking sheet. Bake for 20-25 minutes until the cookies are dry and starting to brown ever so slightly. Remove to wire wracks to cool completely (they will continue to crisp up as they cool). Store in an airtight container at room temperature.