Preheat the oven to 350º degrees. Combine the milk and vinegar in a bowl and set aside to sour-approximately 5-10 minutes.
In a mixing bowl combine flour, cornmeal, sugar, baking soda, and salt.
Once the milk has soured and has thickened slightly, whisk the eggs into the milk.
Stir the dry ingredients into the batter *just* until blended. Tip: I use a large wire whisk to stir the ingredients together.
Melt butter in a 10- or 12-inch cast-iron skillet. Pour in the batter. Pour the heavy cream into center but DO NOT stir, then slide the skillet into the oven and bake until golden brown on top, about 45 minutes.
To serve: slice into wedges and serve warm with a light drizzle of real maple syrup if desired.