1In 1-quart saucepan, heat jelly to boiling. In small bowl, mix cornstarch and 1 tablespoon water; stir into jelly. Heat to boiling, stirring constantly. Boil and stir 1 minute. Cool completely.
2Bake and cool cake as directed on box for angel food (tube) pan. Remove from pan.
3In medium bowl, gently fold cinnamon into whipped topping. Spread on top and side of cake. Arrange peach slices on top. Stir glaze; spread over peaches and top of cake, allowing some to drizzle down side. Store in refrigerator.