Melt butter in large skillet. Remove from heat and stir in sugar. Quickly add eggs to skillet and beat until well blended. You'll want to have both eggs ready and crack them very quickly - the mixture is hot enough that the eggs could begin to cook.
Combine buttermilk with baking soda and stir into mixture in pan. Stir in cornmeal, flour, and salt until well blended and few lumps remain.
Bake in the preheated oven for 30 to 40 minutes, or until a toothpick inserted in the center comes out clean.
Recipe by In Good Taste at http://ingoodtaste.kitchen/caramelized-onions/