In a stand mixer bowl, combine flour and salt. Using a pastry cutter, cut in the cold butter until the mixture becomes coarse crumbs. Snap the butter between your fingers if needed to combine the flour and butter. It's ok if there are little chunks of butter. That's what will make your pastry flaky.
In a separate cup, beat the egg yolk, reserving the egg white until later. Stir the cold water into the yolk. Gradually add the egg mixture to the flour mixture until dough comes together to form a ball.
On a floured pastry mat, roll out half of the dough large enough to cover the bottom and sides of an ungreased 9x13 inch pan. Place the dough in the pan.
Sprinkle the crushed cornflakes over the bottom of the dough in the pan.
Arrange apple slices over the top of the cornflakes. Sprinkle the sugar and cinnamon over the apples.
Roll out the second half of the dough to cover the entire pan with a little dough hanging over the edge. Lay the dough over the filling and pinch the edges of the two crusts together.
Whisk the reserved egg white until foamy and brush onto the top crust with a pastry brush.
Bake the bars for 45 to 50 minutes or until golden brown on top.
To make the almond glaze, whisk the powdered sugar, milk and almond extract until smooth. Drizzle the glaze over the warm apple pie bars.
Serve with ice cream if desired.
Store in an airtight container at room temperature.
Recipe from Allrecipes.comThe calories shown are based on the recipe being cut into 15 bars, with 1 serving being 1 bar. Since different brands of ingredients have different nutritional information, the calories shown are just an estimate. **We are not dietitians and recommend you seek a nutritionist for exact nutritional information. The information in the nutrition box are calculated through a program and there is room for error. If you need an accurate count, I recommend running the ingredients through your favorite nutrition calculator.**