Heat oven to 375 degrees F.
If using crescent rolls: Unroll dough into 1 large rectangle. Press into 12x9-inch rectangle, firmly pressing perforations to seal.
If using dough sheet: Unroll dough. Press into 12x9-inch rectangle.
Cut dough into 12 squares. Gently press squares into 12 ungreased mini muffin cups, shaping edges to form rims 1/4 inch high. Spoon cheese evenly into dough-lined cups. Top each with bacon and onion. In small bowl, beat egg and whipping cream with wire whisk or fork until blended. Spoon slightly less than 1 tablespoon mixture into each cup.
Bake 15 to 20 minutes or until edges are golden brown and filling is set. Cool 5 minutes. Remove from muffin cups.