Using an 8-inch (20-cm) round cake pan, cut a circle out from the puff pastry. Using a fork, poke holes all over the pastry to provide ventilation. Set aside.
3. Step
Cut the tops and bottoms off of the bananas, then halve 2 of the bananas crosswise and set aside.
4. Step
In a large saucepan over medium heat, melt the butter, then add the brown sugar and cook until fully incorporated and the sauce appears amber in color, about 5 minutes.
5. Step
Add the vanilla and cinnamon. Stir until combined.
6. Step
Add the bananas to the pan and cook until softened, about 2 minutes.
7. Step
Turn the bananas to fully coat them with the caramel, then remove from the pan. Reserve the caramel.
8. Step
Grease the cake pan. Arrange the bananas on the bottom of the pan. Pour over the caramel sauce.
9. Step
Cover the bananas with the circle of puff pastry and ensure the edges are tucked into the pan.
10. Step
Bake for 30 minutes, or until the pastry is puffed and golden.
11. Step
Let cool at room temperature for at least 30 minutes before inverting onto a serving plate.
