Place a can of condensed milk in the steamer basket of a pressure cooker. Cover with water, bring to boil and cook for 25 minutes.
Remove the can from the pressure cooker, allow to cool completely before opening and add 2 pinches of cinnamon.
Line 4 small pans with shortcrust pastry, blind-bake, cool, remove from pan then fill with cinnamon milk jam.
Right before serving, cut 2 bananas (not too ripe) in fine slices and arrange in rosettes on top of the jam.
Sprinkle with a little cinnamon, 1 pinch for 4 pies, and serve.