This recipe is healthier than the original in several ways: I reduced the amount of sugar and fat by cutting the amount of streusel topping in half. I added walnuts for fiber and heart-healthy fats. Instead of margarine or butter, I substituted liquid oil (mild olive oil, canola or walnut oil) Given the sweetness of bananas, I used less sugar in the cake itself.
Streusel Topping
¼ cup brown sugar
¼ cup matzah meal
½ cup chopped walnuts
½ teaspoon cinnamon
2 tablespoons oil
Cake
6 large eggs, separated
½ cup white sugar, divided
4 large ripe bananas
2 teaspoons vanilla extract (or 2 packages vanilla sugar)
½ teaspoon salt
½ cup matzah meal
½ cup potato starch
13 x 9 inch (33 x 23 cm) baking pan
Preheat the oven to 325 F (165 C). Oil the baking pan or line the bottom with parchment paper.
In a small bowl, stir together all of the topping ingredients.
Using a food processor, process the yolks with ¼ cup of sugar until they're thick and pale. Slice the bananas and add them to the yolk mixture along with the vanilla, salt, matzah meal and potato starch. Blend until smooth and transfer to a mixing bowl.
Beat the egg whites with an electric mixer until they form soft peaks. Gradually add the remaining ¼ cup of sugar, beating until the whites hold stiff peaks. Fold ¼ of the meringue into the banana mixture to lighten it. Gently fold the rest of the meringue into the batter. Pour the batter into the prepared pan, smooth the top and sprinkle with the streusel.
Bake for 30-35 minutes, until a toothpick comes out clean. Cool on a cake rack.
Chag Sameach V'Kasher to Everyone!