Preheat the oven to 350 degrees F. Line an 8 inch square baking dish with parchment paper so that it overhangs on both sides.
Place the melted vegan buttery spread, sugars, applesauce, vanilla extract, vinegar, and water in a bowl and mix well.
Add the flour, baking soda, baking powder, and salt and stir well. Add the blueberries and fold in gently.
Pour the batter into the prepared pan. Bake at 350 degrees F for 25-28 minutes, or until a toothpick inserted in the middle comes out clean.
Allow the cake to cool, then dust with powdred sugar if desired. Store leftover cake in an airtight container.
Notes
Nutrition facts are for 1/9 of the cake.You can use all-purpose flour if you like.If you want to use coconut oil or canola oil instead of vegan buttery spread, that will work fine.Store leftover cake in an airtight container. It should stay fresh for about 4 days.