Spread the apple filling evenly over the bottom layer. Roll out the second portion of dough and drape it over the top. Pinch the edges together and brush the surface with the reserved egg white. Cut 4–5 slits in the top to vent steam.

Step 5: Bake
Bake at 350°F for 45–60 minutes, until the crust is deep golden brown and the apple juices bubble through the vents.

Step 6: Apply the Hot Glaze
Whisk powdered sugar, vanilla, and milk. Pour over the strudel immediately after it comes out of the oven. Let cool completely in the pan before slicing into squares.