To prepare ice cream, combine first 4 ingredients in a bowl; freeze until firm.
Preheat oven to 350°.
To prepare cake, coat bottom of an 8-inch round cake pan with cooking spray; line bottom with wax paper. Coat wax paper with cooking spray. Combine the sugar and egg in a medium bowl; beat with a mixer at medium speed for 1 minute or until well-blended. Lightly spoon flour into a dry measuring cup; level with a knife. Combine flour, soda, and salt; stir well with a whisk. Add flour mixture to sugar mixture; stir well. Stir in milk, butter, and vanilla. Pour into prepared pan. Bake at 350° for 15 minutes or until a wooden pick inserted in center comes out clean. Cool in pan for 10 minutes on a wire rack, and remove from pan. Cool cake completely on wire rack. Spread the apricot spread over bottom of cake layer, and set aside.
Line a 6-cup glass bowl with heavy-duty plastic wrap, allowing wrap to extend over edge of bowl; place in freezer 10 minutes. Press ice cream into bottom and up sides of bowl; freeze for 30 minutes or until firm. Spoon Watermelon-Cantaloupe Sorbet into center of bowl, pressing firmly. Press cake layer firmly onto top of ice cream, apricot spread side down. Cover and freeze until firm.
Dip bowl into hot water for a few seconds. Place a plate upside down on top of bowl; invert bombe onto plate. Remove plastic wrap, and cut into wedges.