Peel, core and slice apples.
Combine apple slices with 1 cup water, sugar and cinnamon.
Cook on medium heat about 10 mins.
Combine cornstarch with 1/4 cup water; add cornstarch mixture to apple mixture, stirring until thickened.
Cook 5 mins. more. Let cool.
Combine flour, baking powder, and salt.
Cut shortening into the flour mixture.
Add egg yolks, water and lemon juice.
Knead mixture until well mixed.
Divide into two portions. Roll out one portion to fit a 10" x 13" pan.
Fill dough lined pan with cooked apple mixture. Roll out remaining dough and cover apples to fit pan.
Bake in a 425 degree oven for 20 to 30 mins. or until browned.
Combine powdered sugar, salt and lemon juice to spreading consistency while pie bakes.
When pie is ready, remove it from the oven and spread glaze over crust. Serve warm or cold.