1 butter cake mix
1 lg. can (20 oz.) crushed pineapple
1/2 c. sugar
1 stick butter

Mix cake according to directions. Reserve 3/4 cup of batter. Bake cake in a 9 x 13 pan. When cake is done, mix the 3/4 cup of batter, can of pineapple, juice and sugar, and stick of butter in a saucepan. Cook until thick. Pour over cake while still hot. Very good; not too sweet filling.