Melt the chocolate in the microwave by heating in 20 second increments and stirring in between. Add the butter and stir until melted. Set aside.

In a separate bowl, combine the flour, salt, baking powder, espresso, cocoa powder and chocolate chips. Stir until well combined.

In an electric mixer, beat the eggs on low speed and slowly add the sugar and vanilla. Increase the speed to medium and continue to beat until the mixture becomes pale and thick. It should be about 3-4 minutes.

Fold the melted chocolate into the egg mixture. Then fold the flour mixture into the egg and chocolate mixture.

Cover the dough and chill for 30 minutes in the refrigerator or until firm.

Combine the peanut butter, flour and egg whites in a bowl and stir with a spoon until well blended.

Divide the mixture into roughly 12 parts and form small balls. Flatten them into discs that are roughly 1 inch wide.

Preheat the oven to 350°F. Line a sheet pan with parchment paper. Using a cookie scoop, place one heaping scoop of batter on the pan. Place a peanut butter disc on top flattening the chocolate scoop. Place another scoop of batter on top, pressing and covering up any peanut butter on the side.

Repeat for the rest of the batter, leaving 2-3 inches between cookies.

Bake for 10-12 minutes. Allow the cookies to cool slightly on the pan before lifting.