Preheat oven to 350 degrees F. Cut two circles from parchment paper so that they fit in the bottom of two 8 inch round pans.
Lightly grease the bottom of the pans, then press the parchment circles inside. Grease the paper and the sides of the pan as well. Take a small amount of flour and lightly dust the pans. It's very important that you do this so the cakes do not stick to the pan.
Put the melted vegan buttery spread, sugar, and vanilla extract in a mixing bowl, and mix on medium speed to combine.
Add the half the flour, baking powder, salt, water, and vinegar, and mix on low speed to combine. Stop the mixer and add the remaining flour and then mix on low, scraping down the sides as needed.
Divide the batter evenly between the two pans.
Bake at 350 degrees F for about 35-38 minutes, until the top is golden, and a toothpick inserted in the center comes out clean.
Let the cake layers cool in the pans for about 45 minutes, then loosen the edges with a knife and flip the pan over onto a tray a cooling rack. Tap the bottom of the pans with a knife to help the cake release.
Let the layers cool completely before frosting.