Blend the fresh corn, egg, milk, butter, cornflour, all-purpose flour, sugar, and salt together in a blender until smooth and thick, resembling pancake batter.

Preheat a nonstick skillet over medium heat for 3-4 minutes. Drizzle with oil to coat the surface.

Pour a ladle of batter onto the skillet, spreading it into a circular shape about 4-5 inches in diameter. Cook for 2-3 minutes until edges are set and bubbles form on the surface.

Flip the cachapa carefully once bubbles form, revealing a golden-brown color on the cooked side.

Add sliced jalapeños on top of the cachapa before flipping if desired, and cook for another minute until jalapeños are tender.

Place a generous amount of shredded mozzarella on one half of the flipped cachapa and fold the other half over the cheese. Cook for 1-2 minutes until the cheese melts.

Remove from skillet and repeat the process with the remaining batter, adding oil as necessary.

Serve cachapas warm, ideally right off the skillet, with a dollop of sour cream or yogurt.