1Heat oven to 350ºF. Grease bottom and sides of desired pan(s) with shortening; lightly flour. For cupcakes, place paper baking cup in each of 24 regular-size muffin cups.
2In large bowl, beat all ingredients except chocolate chips with electric mixer on medium speed 30 seconds, scraping bowl constantly. Beat on high speed 2 minutes, scraping bowl occasionally. Fold in chocolate chips. Pour batter into pan(s) or divide among muffin cups.
3Bake as directed below or until toothpick inserted in center comes out clean. Cool 10 minutes; remove from pan(s) to wire rack. Cool completely, about 1 hour. 13x9-inch rectangle 40 to 45 minutes two 9x5-inch loaves 35 to 40 minutes two 8-inch rounds 40 to 45 minutes two 9-inch rounds 35 to 40 minutes two 9-inch squares 35 to 40 minutes 24 regular-size muffin cups 20 to 25 minutes