Preheat oven to 350°.

Sift the flour, 1 Tbsp sugar and salt into a large bowl. Add the shortening and cut into the flour using a pastry knife.

Place egg yolks in a 2/3 cup measuring cup. Fill the remainder of the cup with milk. Add the egg yolk and milk to the dry ingredients and mix well.

Split the dough in half and roll out each piece into a rectangle large enough to cover a 10x15 rimmed cookie sheet.

Cover the cookie sheet with one rectangle of dough. Sprinkle the corn flakes over the crust.

In a separate bowl combine the sliced apples, 1 1/2 c. sugar and cinnamon. Coat apples well and then place on top of corn flake layer.

Place the other rectangle of dough over the apples and pinch the crust together on the edges.

In a small bowl, beat the egg whites until frothy and spread over the top crust.

Bake at 350° for 1 hour.

In a small bowl, whisk together the glaze ingredients. Remove the baked bars from the oven and drizzle frosting over the hot crust.

Allow to cool to room temperature before serving.