Preheat your oven to 350°F (175°C) and line a muffin tin with cupcake liners.
In a large bowl, whisk together flour, sugar, cocoa powder, baking soda, baking powder, and salt.
Add milk, vegetable oil, vinegar, vanilla extract, and green food coloring to the dry ingredients and mix until well combined.
Evenly distribute the batter among the cupcake liners, filling each about 2/3 full.
Bake for 18-20 minutes or until a toothpick inserted into the center comes out clean. Let them cool completely.
Once cooled, use a knife or piping bag to spread or pipe vanilla frosting on each cupcake.
Use black or red decorating gel to draw brain patterns on the frosting to complete the zombie brain look.