1 box yellow cake mix
1 (12 oz.) pkg. frozen strawberries, thawed
2 (20 oz.) cartons Cool Whip

Bake cake in two 9-inch round pans, according to package directions. When cool, slice each layer in two. Mix strawberries with 1 carton Cool Whip. Spread half the mixture on one layer. Add a second cake layer, spread with custard filling. Add a third layer, spread with remaining strawberry mixture. Add top layer. Frost entire cake with remaining carton of Cool Whip. Refrigerate overnight. Serve next day.

CUSTARD FILLING:

1/3 c. sugar
1/8 tsp. salt
2 egg yolks, beaten
1 c. milk
1 tbsp. cornstarch
1 tbsp. butter
1 tsp. vanilla