Preheat oven to 180°C and line a muffin tin with 12 patty cases.
In a small bowl combine white vinegar and dairy-free milk. Set aside.
In a medium bowl, sift flour, baking powder and bicarbonate of soda, and set aside.
Using a handheld mixer or a whisk, mix canola oil, sugar and vanilla until combined. Slowly add dry ingredients, alternating with the milk until cupcake batter comes together, scraping down the sides of the bowl as necessary.
Spoon mixture into patty cases ensuring they are only ¾ full before placing them in the oven for 18 minutes or until lightly springy to touch. Let cool completely before frosting.
Make the buttercream. Using a hand mixer or a stand mixer with the paddle attachment fitted, beat dairy-free spread for 1-2 minutes until creamy. Add in 3 cups of icing sugar and beat on medium until combined. As mixture thickens, add in vanilla and dairy-free milk. If frosting is too thin, add in an extra ½-1 cup of icing sugar until it reaches the right consistency. Add pinch of salt to taste if frosting is too sweet.
Tint the buttercream with a few drops of food colouring if desired otherwise place buttercream into a piping bag, I used a 2D tip, and pipe buttercream on cooled cupcakes.