Apple Slab Pie

Preheat the oven to 350 degrees F (175 degrees C.) Combine 1 ½ cups flour, 1 ½ tablespoons sugar, baking powder, and salt in a large bowl. Cut in ½ cup butter until mixture resembles coarse crumbs. Mix egg yolk and water together until blended; add to flour and mix to form a dough. Roll out dough to fit the bottom of a 10x15-inch pan.

Combine apples and lemon juice in a large bowl; add 1 ¾ cups white sugar, 2 tablespoons flour, and ½ teaspoon cinnamon. Pour filling into pie crust and dot with 2 tablespoons butter.

Combine 1 cup flour, ⅔ cup brown sugar, and 1 teaspoon cinnamon in a medium bowl; cut in ⅔ cup butter until crumbly, then sprinkle over apples.

Bake in the preheated oven until topping is golden brown, about 1 hour.