Preheat the oven to 350°F. Place paper baking cups in muffin pans and coat with cooking spray.
Beat all ingredients at low speed with an electric mixer just until dry ingredients are moistened. Increase speed to medium, and beat 3 to 4 minutes or until smooth, stopping to scrape bowl as needed.
Spoon the batter evenly into baking cups, filling each two-thirds full. Bake for 25 minutes, or until a wooden pick inserted in center comes out clean. Cool in pans on wire racks 10 minutes. Remove cupcakes from pans to wire racks, and cool 1 hour or until completely cool. Frost as desired.
Notes
You can substitute another kind of chocolate cake mix if you'd like.