Preheat oven to 350F. Combine butter and sugar. Mix at medium high speed until light. Add flour, powder, and salt. Beat well. Add extract and cream. Mix well.
Turn dough out and work into a ball. Cut into 4 portions and shape each into a ball. Flatten to a 4 inch circle. Chill in fridge for 10min. Place dough rounds on a baking sheet. Brush tops with beaten egg and sprinkle with coarse sugar. Bake 20minutes. Decrease to 300F. Cut each into 10 slices and then in half. Bake for another 10-20minutes.