Jello Cake

1	box white cake mix
	Water, vegetable oil and egg whites called for on cake mix box
1	box (4-serving size) raspberry-flavored gelatin
1	cup boiling water
1/2	cup cold water
1	container (8 oz) Cool Whip,  thawed (3 cups)
	Fresh raspberries, if desired

1.	Heat oven to 350°F (325°F for dark or nonstick pan).
2.	Make and cool cake as directed on box for 13x9-inch pan.
3.	Pierce cooled cake all over with fork. In small bowl, stir gelatin and boiling water until smooth; stir in cold water. Pour over cake. Run knife around sides of pan to loosen cake. Refrigerate 2 hours. Frost with whipped topping; garnish with raspberries. Store covered in refrigerator. This was a special summertime treat in Arizona since it's nice an cool. I love making it with a variety of flavors; i.e., lemon cake with lime jello, yellow cake with cherry jello, etc.  This is a great make ahead dessert.