Preheat the oven to 350 F. Mix all dry ingredients in a bowl (two types of flour, baking powder, salt, sugar). In another bowl, mix sour cream, melted butter and eggs.
Combine dry and liquid ingredients, also add corn kernels. Transfer the corn casserole mixture into a baking dish (8*8 inches) that has been sprayed with non stick spray.
Place in the oven and bake for 35-40 minutes or until the top middle of the casserole feels somewhat firm. You can test with a toothpick to make sure it is not wet but with moist crumbs attached in the center.
Place pan on cooling rack for 10 minutes before slicing.