Preheat the oven to 350 degrees F. Butter a 1.5-quart casserole dish.
In a large bowl with an electric mixer, cream together the butter and sugar until light and fluffy, about 3 minutes. Then add the eggs one at a time, incorporating fully between each addition. With the mixer on low, beat in the pineapple just until incorporated. With a rubber spatula, fold in the bread. Pour it into the prepared dish.
Bake in the oven until golden brown and set, 50 to 60 minutes.