If you are using fresh corn cut the kernels away from the cob.
In a blender or food processor add the corn and puree until mostly smooth.
Add the flour, egg, milk, salt and sugar. Blend until mostly smooth. Allow to rest for 5 minutes.
In a non-stick skillet heat a little butter and oil over medium/high heat. Pour 1/6 of the batter into the center.
After 1-2 minutes you should see bubbles forming in the batter. Use a spatula and flip the cachapa over.
Once flipped allow the cachapa to cook on the other side for another 1-2 minutes.
Flip again (to the original, already cooked side) and add the cheese to half. Fold the cachapa so the cheese is in the center.
Cook for another minute to allow the cheese some time to melt, then remove to a plate or cutting board while you cook the rest.
Notes
I like to use both a rubber spatula and a metal spatula to make these. I use the rubber spataula to help shape any edges that may spread too then when I initially pour the batter and also for folding the cachapas over the cheese. The more sturdy metal spatula is for flipping them.
I have a hard time finding queso de mano, which is more traditional for this recipe, so I always use low moisture mozzarella instead. Be sure to use low moisture, it’s usually sold as a block. Higher moisture mozzarella can make the cachapas too wet and harder to work with and handle when eating.
Since I can only make a couple of these at a time I usually put the done cachapas on a large cutting board and over them with a big glass mixing bowl while I cook the remaining batter. This keeps them warm and also helps to melt the cheese a bit more.