Pineapple Bars

1 cup (8 ¼ oz. can) crushed pineapple with juice
1 cup sugar
3 tablespoons cornstarch
1 tablespoon butter or margarine
1 cup water
¾ cup shortening
1 cup packed brown sugar
1 ¾ cup flour
1 teaspoon baking soda
1 teaspoon salt
2 cups rolled oats
In a sauce pan combine 1 cup crushed pineapple and juice , 1 cup sugar, cornstarch margarine and 1 cup water. Cook until thickened. Remove from heat and cool.
Preheat oven to 400 degrees. Cream together shortening and sugar thoroughly. Stir in flour, baking soda, and salt. Mix in rolled oats. Press and flatten half of the mixture over bottom of a 13 X 9 ½ inch greased pan. Spread with cooled filling. Top with remaining crumb mixture, patting lightly. Bake 25 to 30 minutes or until lightly browned. While warm cut into bars and remove from pan