Preheat your oven to 190°C/375°F and grease a 7-inch cake pan and line the bottom with parchment.
Whisk together the cornmeal, flour, sugar, baking powder, baking soda and salt.
In a separate bowl, whisk together the milk, vinegar, agave and oil.
Add the wet ingredients to the dry and whisk until smooth and pour the batter into the prepared cake pan.
Bake for about 45 minutes or until a toothpick inserted in the center comes out clean. If the top starts to brown too much, cover it loosely with aluminium foil and continue baking.
Let it cool about 10 minutes in the pan before removing and placing on a wire rack to cool completely before slicing.