Bars:
Combine 2 cups flour, 1⁄2 cup sugar, salt and baking powder.
Cut in butter until crumbs are the size of small peas.
Stir in egg yolks.
Divide in half.
Press half into a 15x10x1 inch pan.
Combine apples, 3⁄4 cups sugar, 1⁄4 cup flour and cinnamon.
Arrange over the bottom crust. Crumble remaining dough over apples.
Brush egg white overall. Bake at 350 degrees for 40 minutes.
Cool and drizzle with thin powdered sugar glaze.
Glaze:
Combine all ingredients and drizzle over bars.