Preheat oven to 350°.
Coat an 8-inch square pan with cooking spray. Add peaches, and sprinkle with 1/4 cup sugar and vanilla; stir gently.
Lightly spoon flour into a dry measuring cup; level with a knife. Combine flour and next 5 ingredients in a bowl; cut in margarine with a pastry blender until mixture is crumbly. Stir in egg white, almond extract, and sliced almonds. Dollop flour mixture over peach mixture. Coat lightly with cooking spray.
Bake at 350° for 45 minutes or until lightly golden.