Heat oven to 375°F. Unroll 1 can of dough into 1 large rectangle on ungreased large cookie sheet. Press or roll dough into 13x9-inch rectangle, pressing perforations to seal. Brush with honey mustard to within 1/2 inch of edges. Top with ham; sprinkle with cheese.
Cut 14x12-inch sheet of waxed paper; place on work surface. Unroll second can of dough onto waxed paper. Press or roll dough into 13x9-inch rectangle, pressing perforations to seal. With 2-inch bat-shaped cookie cutter, cut 8 evenly spaced bat shapes in dough (do not remove cutouts).
Use waxed paper to lift dough; invert dough onto cheese. Carefully peel off waxed paper. Seal edges with fork.
Brush bat cutouts with beaten egg. Place cookie cutter over 1 bat cutout; sprinkle cutout with poppy seed. Repeat with remaining cutouts. Brush off any stray seeds not on cutouts.
Bake 18 to 25 minutes or until top is deep golden brown. Cut into 8 pieces.