Preheat oven to 375* F. Prepare a 9x9 square pan by coating it with coconut oil or baking spray and by inserting a parchment sling for easy removal. (See above photos).
In a large mixing bowl, combine sugar, plant milk, peanut butter, canola oil, vanilla and vinegar. Whisk really well to combine, making sure that the peanut butter is completely mixed into the other ingredients.
Place a fine mesh sifter on top of the bowl with the wet ingredients, making sure not to allow the sifter to dip into the wets.
Into the sifter add flour, baking powder, baking soda and salt. Sift into the wet ingredients. Whisk until just combined.
Pour batter into prepared baking pan and bake in a 350* oven for 23-26 minutes or until a toothpick inserted into the center of the cake comes out clean.
Cool completely before decorating and serving.