Preheat oven to 375 degrees F (190 degrees C). Lightly butter an 8 inch square baking dish.
Sift together 1 1/2 cups of flour, sugar, salt, and baking powder. Cut in 1/2 cup of butter until the mixture is crumbly. Stir together the egg with the cream and gently mix into the flour until a soft dough has formed. Press into prepared baking dish. Layer the apples into the dish overlapping, in neat rows. Prepare streusel by mixing the brown sugar, 2 tablespoons flour, and cinnamon together in a small bowl. Cut in 2 tablespoons butter until the mixture is crumbly. Sprinkle over apples.
Bake in preheated oven until apples have softened, and topping has browned, about 25 minutes.