In a large skillet melt the butter or margarine. Add the apples and the 1/4 cup sugar. Cook over medium heat for 15 to 20 minutes or until apples are golden, stirring occasionally.
Meanwhile, in a small bowl combine the eggs, the 1/2 cup sugar, flour, lemon juice, water, baking powder, and cinnamon. Beat with an electric mixer on medium speed for 2 minutes or until thoroughly combined.
Spray a 9-inch pie plate with nonstick cooking spray. Arrange cooked apple slices in pie plate. Sprinkle almonds over apples. Pour egg mixture over apple mixture.
Bake in a 350 degree F oven about 20 minutes or until it is lightly browned around the edges and center is set. Cool on a wire rack. Serve warm or chilled. If desired, sift powdered sugar over top. Cut into wedges to serve. Makes 8 servings.