Line 9x13 inch baking pan with aluminum foil, allowing at least 1 inch excess on each 9 inch side. Lightly grease bottom only.
Arrange candy bars in single layer, with space between each bar, crosswise on top of batter. Do not let candy bars touch side of pan.
Bake 40 minutes or until toothpick inserted near center comes out with only a few moist crumbs on it.