1. Preheat the oven to 400F and place a 9-inch cast iron skillet inside. Getting the skillet hot makes a better “crust” on the bottom of the cornbread.
2. Make the batter: In a large bowl, whisk together the cornmeal, flour, sugar, salt, baking powder and baking soda. Whisk in the milk, buttermilk and eggs. Whisk in almost all of the melted butter, reserving about 1 tablespoon for the skillet later on.
3. Bake the cornbread: Carefully remove the hot skillet from the oven and coat the bottom and sides with the remaining butter. Pour the batter into skillet and place it in the center of the oven. Bake until the center is firm and a cake tester or toothpick inserted into the center comes out clean, 20-25 minutes. Allow to cool for 10-15 minutes and sprinkle with a light layer of granulated sugar for texture. Remove from the oven and allow the bread to cool for a few minutes before slicing.

Jam

1. In a small pot over low heat, warm the jam until it starts to lose shape and become slightly liquid. Stir in the blueberries, salt and lemon zest and transfer to a bowl to cool for a few minutes. Serve alongside the corn bread.