In a large saucepan, bring the 1 cup dairy-free buttery spread or sticks and water to a boil. Remove the pan from the heat.
Add the flour, sugar, eggs, dairy-free sour cream, 1 teaspoon vanilla extract, baking soda, and salt to the buttery mixture in your pan. Whisk the ingredients together until smooth.
Pour the batter into your prepared baking pan and even it out.
Bake for 20 to 22 minutes, or until the cake is golden brown and a toothpick or cake tester inserted in the center of the cake comes out relatively clean with just a few crumbs clinging to it.
Let the cake cool for 20 minutes.
Vanilla Frosting
In a medium saucepan, bring the ½ cup dairy-free buttery spread or sticks and milk beverage to a boil. Remove the pan from the heat.
Mix in the powdered sugar and ½ teaspoon vanilla extract until smooth.
Spread the frosting over the warm cake. Let the cake cool completely before serving.
When ready to serve, cut the cake into 24 pieces. Tightly cover any leftovers.