Preheat oven to 350°F (175°C). Line a 12-cup muffin tin with cupcake liners.
In a medium bowl, whisk together soy milk and apple cider vinegar. Let sit for 5 minutes to curdle, creating vegan buttermilk.
In a large bowl, whisk together granulated sugar, oil, and applesauce until well combined.
Add the vegan buttermilk and whisk until smooth.
In a separate bowl, whisk together flour, cornstarch, cocoa powder, baking powder, baking soda, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Stir in red food coloring gel until desired color is achieved.
Divide batter evenly among prepared cupcake liners.
Bake for 20-22 minutes, or until a toothpick inserted into the center comes out clean.
Let cupcakes cool in the pan for 10 minutes before transferring to a wire rack to cool completely.