Combine in medium saucepan 1/2 cup of sugar, cornstarch, Jello, lemon juice, and water.
Cook over medium heat, stirring constantly, until mixture comes to a boil and thickens.
Set aside to cool slightly.
Stir in sliced strawberries.
Tear angel food cake into 1 inch pieces and toss with 2 cups of the Cool Whip.
Press into 9×13 inch pan (I use glass so you can see the pretty layers).
Combine cream cheese, 1/2 cup remaining sugar, and vanilla in mixer bowl.
Beat until smooth.
Stir in remaining Cool Whip.
Spread evenly over cake layer.
Pour cooled strawberry mixture over cream cheese layer, spreading to cover cake evenly.
Refrigerate 2 to 3 hours before serving.
Note: You may substitute a 16 ounce bag of frozen whole strawberries, thawed and chopped, for the fresh strawberries.