Pineapple Bread Pudding

1 cup margarine or butter softened
2 15 1/4 ounce cans unsweetened crushed pineapple, drained
2 cups sugar
1 teaspoon cinnamon
5 cups toasted bread cubes
8 eggs
chopped pecans, optional
whipped cream, optional

In a bowl, beat margarine, sugar and cinnamon with an electric mixer. Add eggs and beat until fluffy. Fold pineapple and bread cubes into the creamed mixture. Pour into the crockpot. Cover and cook on low for 6 to 7 hours or on high for 3 to 4 hours. Before serving top with chopped pecans and whipped topping if desired. Serve warm.