Beat first 5 ingredients at low speed with an electric mixer just until dry ingredients are moistened. Increase speed to medium, and beat 3-4 minutes or until smooth, stopping to scrape sides of bowl as needed.
Place paper baking cups in muffin pans, and coat with cooking spray; spoon batter evenly into baking cups, filling each 2/3 full.
Bake at 350 degrees F for 25 minutes or until wooden pick inserted in center comes out clean. Cool in pans on wire racks 10 minutes; remove cupcakes from pans to wire racks, cool 1 hour or until completely cool.