Pulse the flour, sugar, and salt together in a food processor.

Add the butter to the mixture. Pulse a couple of times and then drizzle in the water as you pulse - working the mixture until the dough comes together.

Knead gently on a lightly floured surface.

Divide into two portions and form into rectangles. Wrap tightly in plastic wrap to keep the dough from drying out. Refrigerate for several hours or overnight before using.

When ready to bake: Preheat the oven to 375 degrees. Let the dough sit out at room temperature for at least 30 minutes before working it. (it will be too stiff to roll right out of the fridge)

Working one portion at a time - roll the dough out on a lightly floured surface. Roll and stretch until it is approximately 9x13 inches.

Transfer the dough to the bottom of a 9x13 baking dish. You can let the edges come up the sides of the dish. Trim any excess that may overhang the top of the dish.

Roll out the second portion of dough in the same way - let it sit while you make the apple mixture. Cover it with a damp cloth or paper towel to keep it from drying out while you work. (you can also prepare it after you add the apple mixture to the pan - but the apples could brown while you prepare this top layer of dough.)

Toss the prepared apples with the sugar, flour, and spices in a large mixing bowl.

Add the vanilla extract and toss again.

Transfer the filling mixture to the prepared crust - spreading into a smooth, even layer.

Top with the additional dough. Crimp and fold the dough layers - make sure to cover and enclose the apple filling completely.

If you want an extra flaky and golden crust, brush lightly with water or an egg wash before baking. You can also sprinkle some raw sugar on top for added visual interest.

Bake for 45-50 minutes - or until the crust is golden.

Remove and cool at room temperature for about 30 minutes.

Whisk the confectioner’s sugar, milk, and vanilla extract in a small bowl. The mixture should be smooth and glossy.

Drizzle our pour over the top of the slab pie while it is still warm.

Serve warm with a scoop of vanilla ice cream on the side.