In a large mixing bowl combine egg whites, whole egg, granulated sugar, honey, liqueur, vanilla, and salt; beat with a wire whisk or an electric mixer on low speed until light and frothy. Stir in the yogurt until mixture is smooth. Add flour; beat until mixture is smooth.
Grease six 6-ounce individual quiche dishes. Arrange berries in bottom of dish. Spoon batter over berries. (Batter will not cover berries completely.) Bake in a 375 degree oven for 20 to 25 minutes or until center appears set when shaken. Cool on a wire rack for 30 minutes.
Just before serving, if desired, sprinkle with powdered sugar. Makes 6 servings.