Line 2 cake pans of each tier size with plastic wrap, allowing a 2-inch overhang. Put gelatin sheets into a bowl of cold water. Let soften 5 minutes. Squeeze out excess water from sheets; set sheets aside.Advertisement
Bring half of the jam to a boil in a medium saucepan over medium-high heat. Remove from heat. Add gelatin sheets, and stir until gelatin has dissolved. Stir in remaining jam. Pour into prepared pans. Refrigerate until firm, 3 hours or overnight.