Get ready for finish-to-start giggles when kids turn their world inside out and upside down. Run the party in reverse order -- start by spelling everything backwards, including the "Happy Birthday!" on the cake. Ask guests to dress in backwards attire and have the balloons hang upside down from your ceiling. Eat your feast under the table, and send guests home with sweet treats and bracelets!
1 tube (4.25 oz.) yellow decorating icing, fitted with a star tip
1/3 cup colored sprinkles
Candy letter decorations
Heat oven to 350°F. Prepare batter and divide in two 8-inch round cake pans. Sprinkle batter with chocolate chips. Bake according to package directions. Transfer to wire rack and cool 10 minutes; invert and cool completely.
Level cakes. Fill and frost cake layers with vanilla frosting. Make a decorative border around rim with yellow frosting. Press colored sprinkles onto sides of cake. Place letter decorations backwards on top of cake.