In a measuring cup, place 1 tablespoon of white vinegar. Next, pour the coconut milk to the one and one half cup line of the measuring cup. (Please note that this recipe also works very well with soy milk.) Allow to stand for 5 minutes. This will allow the milk to thicken and curdle.
Next add the oil and pure vanilla extract, to the measuring cup with the milk and vinegar mixture.
In a mixing bowl, add all of the dry ingredients, including the all purpose flour, sugar, baking powder, baking soda and salt.Pour the wet ingredients onto the dry and mix until there are no more lumps. I use a scraping attachment of my standing mixer to achieve a smooth batter.
If you are just making Vegan Vanilla cake or cupcakes, you can stop here. If you want to make a rainbow, we have to add a few steps.
The easiest and best way to make a rainbow is to measure all of the wet ingredients into separate batches, using separate measuring cups. To make a rainbow, I lined up 6 mason jars. If you are making a small batch, I recommend only making 3 recipes so that you can split each batter up and color them. This should yield about 18 cupcakes. If you need to make a larger number of desserts, I recommend making six total batches and coloring them separately.
Once the batter is smooth, add the food coloring. To make a rainbow, you need red, orange, yellow, green, blue and purple. My kids supervised the whole project, to be sure I was accurate. I use gels and squirt them in. I'm guessing it's about a 1/2 teaspoon per batch. You can add more, depending on how vibrant you want to colors of the cake to be. I place each colored batch into gallon-sized ziplock bags.
Preheat your oven to 350 degrees.
When your cupcake tins are lined with paper cups, it's time to get to work. Cut a very small hole at one corner of the first bag of batter and pipe in a small amount to cover the bottom. Go up from there until you have purple. It's important that you hit the edge of the paper with the batter, for the best result. The most beautiful part of the cupcake is the rainbow line that can be seen on the wrapper. You will want as little batter of each color as possible per cupcake. You'll end up with very full cups, no matter how hard you try for them to be the typical 2/3 up. It's OK and it will all work out in the end.
Place in the oven for 16-18 minutes, or until the center of the front cupcakes test dry. Allow to cool before frosting. I used gold, edible luster dust as the finishing touch to this cupcake.