Heat oven to 350°F.
Generously grease bottom, sides and rim of two 9 inch pie pans. (Do not substitute 8 inch pie pans.)
In large bowl, combine cake mix, 3/4 cup of the frosting and water.
Blend at low speed until moistened; beat 2 minutes at high speed.
Spread half of batter (2 1/4 cups) in bottom of each greased pan.
Do not spread up sides of pan.
Bake at 350°F. for 20 to 27 minutes or just until center is set.
DO NOT OVERBAKE.
Cakes will collapse to form shells.
Cool completely.
Spoon ice cream evenly into each shell.
In small saucepan over low heat, heat remaining frosting just until melted, stirring occasionally.
Drop by teaspoonfuls over ice cream; lightly swirl with tip of knife.
Freeze until firm.
Cover; freeze until serving time.
Let stand at room temperature 10 to 15 minutes before serving.