Soak sliced bananas in pineapple juice for 20 to 30 mins.
Drain saving the juice.
Place bananas in pastry lined pie plate, add sugar and cinnamon which have been mixed together.
Add 2 tbs. of the pineapple juice.
Dot with butter and cover with top crust.
Bake at 400°F.for 30 to 45 minutes, or until crust is browned.