Beat butter and cream cheese in bowl of electric mixer until light. Beat in the flour and cream, alternating the flour and cream, until well mixed. The dough will be very soft. Divide into 4 portions and wrap in plastic wrap. Refrigerate overnight.
Preheat oven to 350º and have ungreased cookie sheets ready.
Sprinkle work surface and rolling pin with powdered sugar. Roll out dough portion to about ¼-inch thickness. The dough is really hard to roll at first but then gets easier. If it tears a little in spots, just pinch it back together. Use a small round cutter (2-inch diameter) to cut out cookies and place on baking sheet, about 1 - 2 inches apart.
Make a small depression in the center of each with your fingertip. I used, and prefer, the bottom of a shot glass which I dipped in powdered sugar so it wouldn't stick. Works better for me than with my fingertip. Fill cookies scantily with jam, jelly, preserves, cheese or nut filling. If you use too much filling, it will run out onto the baking sheet.
Bake until bottoms are lightly browned, about 12 - 15 minutes. Cool on wire rack and sprinkle generously with powdered sugar while still warm.