Preheat the oven to 350. Grease 1 or more cookie sheets.
Using a mixer on medium speed, cream the butter and both sugars in a bowl until fluffy. Add the eggs and vanilla; beat well.
In a small bowl, combine the flour, cocoa and baking powder. Gradually add to the butter mixture, beating until blended. Stir in the baking pieces. Drop by tablespoonfuls, 2 inches apart, onto the prepared cookie sheets. Bake 12 to 14 minutes. Cool on a wire rack.
In a small bowl, combine the confectioners' sugar, milk and raspberry preserves. Stir until smooth. When the cookies have cooled, drizzle the icing over them.
Photograph by Miki Duisterhof