Set oven to 350.
Open cans of pineapple and strain; set aside.
Melt 2 sticks of butter; let cool.
Mix together eggs and sugar, then add vanilla.
Turn mixer on slow and add cooled butter.
Dice up the 12 slices of bread and put in a bowl.
Add crushed strained pineapple to bread mix, then egg mixture. Mix to combine.
Make sure all the bread is covered, then pour in a 9×12 greased pan.
Sprinkle with cinnamon.
Cover with foil and bake for 45 minutes.