Slice the prepared cocoa sponge cake in two horizontally. Sprinkle cakes with Grand Marnier.
Place one cake on a heatproof plate or platter, arrange strawberries over cake, top with remaining cake.
Soften ice cream slightly, spoon onto cake, shape into a dome, cover, freeze until firm.
Beat egg whites in a medium bowl with an electric mixer. until soft peaks form. Gradually add sugar while beating.
Spoon meringue into a large piping bag fitted with a tube. Starting with the base of the cake, pipe mixture evenly around cake and ice cream until completely covered.
Bake in a 500 degree oven for about 3 minutes or until meringue is lightly brown.
Serve immediately.