Heat the oven to 375 degrees and line a baking sheet with parchment paper.
In a large bowl, combine the ground beef, corn, breadcrumbs, egg, onion, garlic, chili powder, cumin, cayenne, salt, and black pepper. Mix with your hands until evenly blended.
Divide the mixture into four equal portions and shape each into a small loaf. Place the loaves on the prepared baking sheet.
Bake the meatloaves for 25 minutes.
While the meatloaves bake, place the potatoes in a large pot and cover with water. Bring to a boil and cook until tender, about 15 minutes. Drain the potatoes.
Return the drained potatoes to the pot. Add the butter, milk, and a pinch of salt. Mash until smooth.
Remove the meatloaves from the oven. Spoon the mashed potatoes evenly over each loaf and sprinkle with the cheddar cheese.
Return the sheet to the oven and bake for 10 more minutes, until the cheese melts and the tops turn lightly golden.