Prepare ingredients. If using buttermilk powder, add water according to instructions and mix vigorously until homogenous. Allow to sit. Shred cheese and set aside; melt butter in a microwave safe bowl. Coat a 9"x13" baking pan with cooking spray or butter and set aside.
Add 1 cup flour, 1 cup cornmeal, 1 Tbsp baking powder, ½ cup sugar, and ½ cup pepperjack cheese to a large bowl, and mix together loosely. (Optional) If you prefer more spice than just the pepperjack cheese, add a pinch of red pepper flakes.
Add in the wet ingredients: buttermilk, eggs, creamed corn, chilis, and melted butter. Mix until combined. Batter will be wet but thick.
Pour the batter into the pan and sprinkle cheddar cheese on top.
Bake for 23-26 minutes or until center no longer jiggles. If served immediately from the oven the cornbread can have more of a soft "souffle" texture, but it will continue to firm as it cools. Allow to cool fully before cutting into squares and serving.