Over a large bowl, sift together all-purpose flour, baking powder, salt, sugar. Cut in butter and blend with a pastry blender until mixture resembles cornmeal. Stir in lightly beaten egg, cream, and vanilla. Blend well. Dough may be chilled, if desired.
On a floured surface, roll out dough to 1/8 inch thickness. Sprinkle with sugar; cut into desired shapes. Transfer to ungreased baking sheets.
Bake for 6 to 8 minutes, or until delicately brown.