Prep the pans and oven: Heat the oven to 350°F (175°C). Line a 12-cup muffin pan with paper liners. If you have two pans, line both and bake in batches for up to 18 cupcakes.
Mix dry ingredients: In a large bowl, whisk 2 cups all-purpose flour, 3/4 cup granulated sugar, 1 tablespoon unsweetened cocoa powder, 1 teaspoon baking soda, and 1/2 teaspoon fine sea salt.
Whisk the wet ingredients: In a separate bowl, combine 3/4 cup buttermilk, 2 large eggs, 1/4 cup melted unsalted butter (cooled), 1/4 cup neutral oil, 1 teaspoon vanilla extract, and 1 teaspoon white vinegar.
Add 1–1.5 teaspoons green gel food coloring. Start with less and adjust for your ideal shade.
Combine gently: Pour the wet ingredients into the dry. Whisk or fold just until smooth. Do not overmix or you’ll lose the velvety texture.
Portion: Fill liners about two-thirds full.
A large cookie scoop makes this quick and even.
Bake: Bake 16–19 minutes, or until the tops spring back and a toothpick comes out with a few moist crumbs. Avoid overbaking.
Cool: Let cupcakes rest in the pan 5 minutes, then move to a wire rack to cool completely before frosting.
Make the frosting: Beat 8 ounces cream cheese and 1/2 cup unsalted butter until smooth and fluffy, 2–3 minutes. Add 2.5–3 cups powdered sugar, 1 teaspoon vanilla, and a pinch of salt.
Beat until creamy and pipeable. Adjust powdered sugar for thickness.
Frost: Spoon or pipe the frosting onto cooled cupcakes. For a simple finish, use a round or star tip.
Add sprinkles or grated white chocolate if you like.