Scalloped Pineapple

Similar to a pineapple bread pudding, the butter gives it a rich flavor.

½ unsalted butter, room temp.
1/3 C applesauce
1 ¼ C sugar
1 can (20 oz) pineapple tidbits, drained
2 whole eggs, beaten
1 ½ tsp. lemon juice
2 egg whites, beaten
4 C firmly packed white bread cubes