Abstract: A tray is assembled by automated equipment from a die cut blank. Tabs on opposing ends of side pieces are enfolded in rolled ends. A serrated edge on a distal edge of each rolled end is placed into a slit and crushed area to interlock the distal edge with the blank and form a tray with interlocked walls. The serrated edge does not penetrate the die cut blank, thus providing a leakproof, interlocked tray. Perforations define various fold lines to facilitate the use of automated equipment to form the tray. Release paper is placed on the central portion of the tray, with cake batter placed on the release paper. The batter can be baked into a cake while still in the tray.