1 (14 oz.) can sweetened condensed milk (not evaporated milk)
1 1/2 c. cold water
1 pkg. (4 serving size) instant vanilla flavor pudding and pie filling mix
2 c. Cool Whip
36 vanilla wafers
3 medium bananas, sliced and dipped in lemon juice

Prepare the cake according to directions, making two (8-inch) layers. Split both horizontally after they have cooled. Blend together the sugar, sour cream and coconut and chill. Spread all but one cup of the sour cream mixture between the four layers. Blend the remaining cup of the mixture with the whip cream and spread on the top and sides of the cake. Seal in an airtight container and refrigerate for three days before serving. Keep refrigerated after cutting.