1 lemon cake mix, prepare by directions on box
8 oz. Cool Whip
1/2 c. lemon juice
1 cans sweetened condensed milk (Eagle Brand)

Cook cake according to package directions in 9 x 13 dish. While cake is cooking and nearly done, melt butter over low heat in saucepan. Add cocoa, sugar and milk and bring to a boil. Boil for 2 minutes, stirring constantly. Remove from heat. Poke holes all in cake while it is hot and pour heated mixture over cake.