Heat oven to 450°F. Unroll pie crusts on work surface. With rolling pin, roll each crust lightly into 12-inch round. With 3-inch round cutter, cut 24 rounds from crusts, rerolling scraps as necessary. Press 1 pie crust round in bottom and up side of each of 24 ungreased mini muffin cups, so edges of crusts extend slightly above sides of cups.