Place the puff pastry sheets side by side on a baking sheet and brush with crème fraîche. Then cut the banana into slices, spread it on the puff pastry and sprinkle everything with cinnamon. Sprinkle the brittle on top and put the whole thing in the oven for 15 minutes at 200 °.
After baking, put a scoop of vanilla ice cream on each sheet of dough.