These cookies are decorated beautifully and are perfect for parties.
Cream together butter and sugar. Beat in egg, zest, and liqueur. Mix until smooth. Sift together flour, baking powder, and salt, and add slowly to the butter mixture. Stir in chocolate. Beat well.
Chill dough for several hours.
Heat oven to 325 degrees.
Roll dough 1/4 inch thick and cut into shapes.
Bake for 15 minutes, or until golden.