Blend the Batter: In a blender, combine sweet corn, egg, flour, salt, and sugar. Blend until mostly smooth with some texture. Set aside for 5 minutes.

Heat the Skillet: Heat a non-stick skillet over medium heat and add vegetable oil. Wait until the oil shimmers.

Cook the Cachapas: Spoon 60 ml of batter into the skillet for each cachapa. Cook for 3-4 minutes until edges are golden, then flip and cook for another 3-4 minutes.

Add the Cheese and Fold: Place a slice of mozzarella in each cachapa's center, cook for an additional minute, then fold in half to melt the cheese.

Serve the Cachapas: Remove from skillet, add a pat of unsalted butter on top, and serve warm.