Instructions
1. Prepare the Apple Filling
In a large bowl, toss the sliced apples with sugar, flour, and cinnamon until coated evenly. Set aside to allow the apples to release their natural juices while you make the crust.
2. Make the Crust
In another bowl, combine flour, salt, and sugar. Cut in the shortening with a pastry cutter or fork until the mixture resembles coarse crumbs. In a measuring cup, combine the egg yolks and enough water to make 1 cup total. Stir into the flour mixture until a dough forms. Divide the dough in half.
3. Roll Out the Bottom Crust
Roll one half of the dough into a rectangle large enough to line a 10×15-inch jelly roll pan. Press evenly into the pan, extending slightly up the sides.
4. Add the Filling
Spread the apple mixture evenly over the bottom crust, distributing it from corner to corner.
5. Roll Out the Top Crust
Roll the second half of the dough into a rectangle and place it over the apples. Seal the edges by pinching or crimping. Brush the top with the reserved egg white for a golden finish. Cut a few slits in the top to let steam escape during baking.
6. Bake
Bake at 350°F (175°C) for 45–60 minutes, or until the crust is golden and the filling is bubbly.
7. Make the Glaze
While the strudel bakes, whisk together powdered sugar, vanilla, and just enough milk or cream to create a thin glaze.
8. Glaze and Serve
Spread the glaze over the hot strudel straight from the oven. The icing will soak slightly into the crust, adding sweetness and shine. Let cool before slicing into squares or bars.
