Blueberry Sandwich Bars

Preheat the oven to 375 degrees F. Grease a rectangular pan Crust?In a medium bowl, stir together sugar, flour and baking powder. ?Use a fork to blend in the butter and egg white.?Dough will be crumbly but not too dry. If needed ad a little water. Pat half of dough into the prepared pan. Press down tight. Filling: In a blender, blend sugar, cornstarch and blueberries. Sprinkle the filling evenly over the crust. Place remaining dough over the berry layer. Bake in preheated oven for 40 minutes, or until top is slightly brown. Cool completely before cutting into rectangles. Garnish with fresh blueberries.