Cupcakes:
Preheat the oven to 350 F (180 C).
Line a 12-cup muffin tin with paper liners.

In a bowl, combine the pureed bananas, buttermilk, melted butter, egg, and vanilla extract. Set aside.
In another bowl, combine the flour, cinnamon, baking powder, baking soda, and salt.
Add the wet ingredients to the dry ingredients and mix with a fork until just combined.

Divide the batter evenly among the muffin cups and bake for 20 minutes.
Let the cupcakes cool completely on a wire rack.

Glaze: Using an electric mixer, cream the cream cheese and butter, then add the dulce de leche and powdered sugar.
Beat until smooth.
Transfer the mixture to a piping bag fitted with a star tip and frost the cupcakes.