Preheat the oven to 400 F (204 C)
Grease an 8 or 9-inch round or square pan. A cast-iron skillet will work as well. Set aside.
In a small bowl, add in 1 tablespoon ground flaxseed meal and 3 tablespoons of water. Mix together, and let sit for 15 minutes to set up and thicken.
In another small bowl, whisk together 1 1/4 cup unsweetened almond milk and 1 tablespoon white vinegar. Let sit for a few minutes to develop into buttermilk.
Weigh the flour and cornmeal; or measure each by gently spooning into a cup, then sweeping off any excess. In a large bowl, whisk together the flour, cornmeal, sugar, baking powder, baking soda, and salt.
Pour the wet ingredients into the dry ingredients and whisk until combined. Avoid over-mixing.
Pour batter into prepared baking pan. Bake for 20-25 minutes or until golden brown on top, edges are crispy and pulled away from the pan, and a toothpick inserted in the center comes out clean.