Step 1
Preheat the oven to 350°F. Line 24 muffin cups with paper liners.
Step 2
Follow the box instructions, putting all the ingredients in a large bowl and using the buttermilk in place of the water specified, using the amount of vegetable oil that is called for, and adding the eggs. Beat with an electric mixer until moistened, about 30 seconds. Increase the speed to high and beat until thick, 2 minutes longer.
Step 3
Spoon half the batter into a ziplock bag. Snip 1/4 inch corner from the bag and fill the paper liners two-thirds full. Repeat with the remaining batter. Bake until golden and a toothpick inserted in the center comes out clean, 15 to 20 minutes. Remove the cupcakes from the baking pans, place on a wire rack, and allow to cool completely.