Preheat the oven to 180°C/350°F. Line one muffin tin with 12 patty cases/cupcake liners and a second tin with 2.
In a small bowl, combine the 250 ml dairy free milk and 2 tablespoons white vinegar. The milk may split, which is fine. Set aside.
In a medium bowl, whisk together the 300 grams plain flour/all purpose flour, 2 tablespoons cocoa powder, 1 ½ teaspoons baking powder, ½ teaspoon bicarbonate of soda/baking soda and ¼ teaspoon salt.
In a large bowl, whisk together 180 grams white sugar/granulated sugar, ⅓ cup canola oil, and 2 teaspoons vanilla extract until combined.
Slowly add the dry ingredients to the oil and sugar mixture, alternating with the milk, until the batter comes together, scraping down the sides of the bowl as necessary.
Add the ¼ teaspoon red gel food colouring, if using, and mix through, adjusting until you reach your desired colour. You can let the batter sit for 5 minutes for the colour to develop further.
Spoon the batter into the patty cases, filling them only ½ full. Bake for 20 minutes, or until lightly springy to the touch. Let cool completely before frosting.