Preheat oven to 350 degrees F. Lightly grease baking sheets.
With an electric mixer, beat butter and sugars together at medium speed until fluffy. Add eggs and vanilla, beating well.
In a small bowl, combine flour, cocoa, and baking powder; gradually add to butter mixture, beating until blended. Stir in baking pieces. Drop cookies by tablespoonfuls onto prepared baking sheets. Bake 12 to 14 minutes.
Remove to wire racks to cool. Once cool, drizzle with Raspberry Icing.
Raspberry Icing:
1 1/2 cups confectioners' sugar
2 tablespoons milk
1 tablespoon seedless raspberry preserves
In a small bowl, combine all ingredients, stirring until smooth.