In a bowl, mix together the flour, oatmeal, brown sugar, melted butter or margarine, and cinnamon. In a
greased 9x13 inch pan, press down 1/2 of preceding mixture.
In a pan, cook corn starch, vanilla, sugar, water, and salt until thickened. Put sliced apples in and mix together.
Pour this mixture over
crust in a 9x13inch pan. Sprinkle the rest of the dry mixture over the apple mixture. Bake at 350° for 40 to 50 minutes.