Arrange the slices of Swiss roll or trifle sponge, well spaced apart, on a baking sheet, then top each with a scoop of ice cream. Put into the freezer for 10 minutes (or longer if you have time).
Whisk the egg whites in a large bowl until stiff, moist-looking peaks form. Gradually whisk in the sugar, a teaspoon at a time, and continue whisking for a few minutes until thick and glossy (see
Take the sponge and ice cream from the freezer and quickly swirl the meringue over the top and sides to cover completely. Cook in a preheated oven, 200°C (400°F), Gas Mark 6, for 5 minutes until the peaks are golden brown, the meringue is cooked through and the ice cream only just beginning to soften.
Transfer the baked Alaskas to shallow serving bowls and spoon the summer fruit around the base of the desserts. Serve immediately.