In a small saucepan, combine chocolate and butter. Cook over low heat until both have melted.
Stir until smooth and set aside.
In a small bowl, combine flour, baking powder, and salt. Set aside.
In a mixing bowl, beat together the eggs, sugar, and vanilla until mixture begins to thicken.
Stir in cooled chocolate mixture, followed by flour mixture.
Beat until combined. Let batter stand 10 minutes in order to thicken up.
Preheat oven to 375 degrees.
Drop dough by tablespoon onto a lined baking sheet, keeping each cookie about 2 inches apart.
Bake for 8 minutes, or until edges are set and cookies are slightly cracked.
Let cool for 1 minute before removing to a cooling rack.
Prepare the frosting. In a mixer bowl, combine butter and peanut butter, beating until smooth.
Slowly mix in powdered sugar one cup at a time, mixing well after each addition.
Add in vanilla and cream and beat until frosting is spreadable consistency, adding more cream if necessary.
Stir in mini chocolate chips.
To assemble, pipe or spread a generous spoonful of frosting over the bottoms of 6 cookies.
Top each with remaining cookies.