Preheat your oven to 425°F. Put the bacon grease in your cast iron skillet or baking dish and put that in the oven while it's preheating.
1 tbsp bacon grease
Mix all the dry ingredients together well.
1 cup medium grind cornmeal, 1 tsp baking powder, 1/2 tsp baking soda, 1 tsp kosher salt, 2/3 cup fine grind cornmeal or corn flour
Mix the buttermilk and the eggs together until fully combined.
1-1/4 cup buttermilk, 2 large eggs
Combine the wet and dry ingredients.
Add the melted butter and continue mixing until the butter is fully incorporated.
6 tbsp butter
Allow the mixture to rest for 10 mins before baking. This will also give your oven time to fully preheat.
Carefully pour the batter into the preheated skillet/baking dish, being careful not to splash any grease onto the oven (or yourself).
Reduce the heat to 375°F and cook until the top is lightly browned and a toothpick inserted into the center comes out dry. (About 30-40 mins)
Remove from the pan immediately and allow to cool for about 10 minutes before cutting and serving.