Combine sprouted flours, salt, baking powder, and baking soda in a large bowl.
In another bowl combine sourdough starter, milk, eggs, and maple syrup.
Stir well, add melted butter, and stir again.
Pour wet ingredients over dry and mix just until thoroughly moistened.
Pour batter into a 2-quart buttered glass baking dish.
Bake at 400°F for 20 to 25 minutes, until golden brown and a toothpick inserted in center of bread comes out clean.
Serve piping hot with fresh cultured butter and honey.
Note: If you do not have access to sprouted flours you can use regular wheat flour in place of the sprouted wheat flour and organic masa harina in place of the sprouted corn flour. Soak the flour and masa overnight in the buttermilk and then combine with remaining ingredients in the morning.