Preheat the oven to 350 degrees and add cupcake liners to a muffin tray.
In a small bowl, whisk together the almond milk and the apple cider vinegar. Set aside. In a medium mixing bowl, add the all-purpose flour, sugar, baking powder and salt. Whisk together.
Add the almond milk/apple cider vinegar to the flour mixture along with the vegetable oil and vanilla. Whisk until combined. Fill the liners until they are slightly more than 1/2 full. are for 22-24 minutes or until a toothpick inserted into the center comes out clean. Place them on a cooling rack.
For the frosting
Make sure the cupcakes are throughly before decorating. While the cupcake are cooling, prepare the vegan buttercream frosting. Add the room-temperature butter to a stand mixer bowl (or use a mixing bowl and hand mixer). Beat until smooth (about 2 minutes).
Add the powdered sugar and and mix until it is incorporated. Add the pure vanilla extract and mix until combined. If your icing is too thick, you can add 1 tbsp of almond milk at a time. If it is too thin, add more powdered sugar.