This dessert can be made one day ahead and stored in the freezer, making it ideal for entertaining. You can create the decorative meringue swirls and peaks with a rubber spatula, table knife, or spoon, but an offset spatula works best.
Bake cake until top is golden and tester inserted into center comes out clean, about 28 minutes. Cool completely in pan on rack. Remove pan sides.
03Line 4-quart 10-inch-diameter bowl with plastic wrap, leaving 8-inch overhang. Spread sorbet in even layer over bottom (not sides) of bowl. Spread ice cream over sorbet. Place cake atop ice cream, pressing slightly to compact. Cover with plastic wrap overhang; freeze at least 4 hours or overnight.
04Using electric mixer, beat egg whites in large bowl until soft peaks form. Gradually beat in sugar, 1 tablespoon at a time; beat until thick and glossy. Beat in vanilla.
05Unfold plastic wrap from over cake at top of bowl. Invert dessert onto 9-inch-diameter tart pan bottom; remove plastic wrap. Working quickly, spread meringue over dessert, swirling to form peaks and covering completely. Freeze at least 30 minutes. (Can be made 1 day ahead; keep frozen.)
06Preheat oven to 500°F. Place dessert on its tart pan bottom on heavy large baking sheet. Bake just until meringue is light golden, about 5 minutes. Transfer to platter. Serve immediately.