Apple Sheet Cake

3 cups all-purpose flour

1 ½ teaspoons baking powder

1 teaspoon salt

½ cup shortening

1 cup milk

3 pounds apples - peeled, cored and sliced

1 cup white sugar

1 teaspoon ground cinnamon

2 tablespoons all-purpose flour

½ cup butter

2 ½ cups confectioners sugar

3 tablespoons milk

⅓ cup butter, softened

½ teaspoon vanilla extract

Preheat oven to 400 degrees F (200 degrees C). In a large bowl, combine 3 cups flour, baking powder and salt. Cut in shortening to the consistency of coarse crumbs. Stir in 1 cup cold milk slowly until completely blended. Separate dough into two balls. Roll out one ball of dough to fit a 15 x 10 inch pan with some dough extending over the edge of the pan.

In a large bowl, combine sliced apples, sugar, cinnamon and 2 tablespoons flour. Place filling in an even layer over prepared crust. Thinly slice 1/2 cup butter and evenly distribute over the apples. Roll out the remaining dough and place over the apple filling. Seal edges and prick the top all over with a fork.

Bake in the preheated oven for 30 minutes. Cool 5 minutes before frosting.

To make the frosting: In a small bowl, combine confectioners sugar, 3 tablespoons milk, 1/3 cup butter and vanilla extract. Beat until smooth and creamy.