Mix flour, margarine and cream. Cover and refrigerate (at least 30 minutes)
Heat oven to 375. Roll about 1/3 of dough at a time, approximately 1/8 inch thick on floured cloth-covered board (keep remaining dough refrigerated).
Cut into 1-1/2" rounds. Coat both sides with sugar. Place on ungreased cookie sheet. Prick each round with fork 3-4 times.
Bake 7-9 minutes, until set but not brown. Remove from cookie sheet and allow to cool. Put cookies together in pairs with filling (see below).
Filling
Mix powdered sugar, softened butter and vanilla until smooth and fluffy. Beat in a few drop of water, if necessary. Filling should have a smooth, spreading consistency. Add food coloring to filling for different holidays.