Preheat oven to 350 ℉. Line 12 jumbo muffin cups with paper liners.
Sift flour, sugar and baking powder into a large mixing bowl.
Add cornmeal and salt, and whisk to combine.
In a separate bowl, whisk together the milk, eggs, and melted butter.
Pour the wet ingredients into the dry and stir until the are just blended. Fold in cheeses and jalapenos.
Spoon or scoop batter into muffin liners, filling almost to the top.
Bake for 18 minutes, or until the tops begin to brown. Remove and top the muffins with an extra sprinkle of cheese. Return to the oven and bake for another 5 minutes.