Powder sugar (optional) For filling, in a saucepan bring water to boiling. Add mincemeat; reduce heat. Cover and simmer for 3 minutes, stirring often. Cool. In a large bowl beat shortening with an electric mixer on medium speed for 30 seconds. Gradually add granulated sugar, beating till fluffy. Beat in molasses. Add flour; beat till combined. Use a wooden spoon to stir in oats. Press one/half of the oatmeal mixture onto the bottom of a greased 9x9x2-inch baking pan. Spread mincemeat filling onto oatmeal mixture.
Drop remaining mixture by teaspoonsfuls onto filling. Bake in a 350 degree oven for 35 minutes or till light brown. Cool in the pan on a wire rack. If desired, sprinkle with powdered sugar. Cut into diamonds or bars. Makes 24 servings.