In the bowl of a food processor or a standing mixer, whirl or beat almond paste and 1 cup sugar until well blended. Whirl or beat in egg whites, matzoh cake meal, and salt until well incorporated (mixture will resemble very wet cookie dough).
In a large bowl, mix apples, strawberries, lemon juice, potato starch, and remaining 1 tablespoon sugar. Spread fruit mixture level in a shallow 2 1/2- to 3-quart baking dish. Pat al-mond paste mixture evenly over fruit.
Bake in a 350° oven until topping is browned and fruit bubbles, 40 to 45 minutes. Let stand at least 10 minutes.