1Heat oven to 375°F. Place paper baking cup in each of 12 regular-size muffin cups. In large bowl, beat all cupcake ingredients with electric mixer on low speed 30 seconds, scraping bowl frequently. Beat on medium speed 2 minutes, scraping bowl occasionally. (Batter will be thick.) Divide batter evenly among muffin cups, filling each half full.
2Bake 18 to 20 minutes or until toothpick inserted in center comes out clean. Remove from pan to cooling rack; cool completely, about 30 minutes.
3In small bowl, mix powdered sugar and cocoa. In large bowl, beat 1/2 cup butter on medium speed 2 minutes or until creamy. Add powdered sugar mixture alternately with 1/4 cup milk, beating on low speed until blended. Beat in 1 teaspoon vanilla. Frost cupcakes. Garnish with candy sprinkles. Store covered in refrigerator.