2To prepare cupcakes: Line twelve 2- ½-inch muffin cups with paper bake cups. Coat paper bake cups with cooking spray. (Or grease and lightly flour the muffin cups.) Set aside. In a medium bowl, combine flour, baking powder, baking soda, and salt; set aside.
3In a small bowl, whisk together buttermilk, sugar, oil, egg product, and vanilla extract. Add buttermilk mixture to flour mixture. Beat with a wire whisk just until combined.
4Spoon batter evenly into prepared muffin cups, filling each two-thirds to three-fourths full. Bake for 14 to 16 minutes or until a toothpick inserted near centers comes out clean. Cool in muffin cups on a wire rack for 5 minutes. Remove cupcakes from muffin cups. Cool completely on wire rack.
5To prepare frosting: Beat cream cheese in a bowl with a mixer on medium until smooth. Beat in yogurt and 2 tablespoons cocoa powder until smooth. Beat in powdered sugar until smooth (frosting will thin slightly). Cover and chill 4 to 24 hours before spreading or piping on cupcakes.
6Using a pastry bag fitted with an open star tip, pipe frosting onto cooled cupcakes. If desired, dust with 1 teaspoon cocoa powder. Store frosted cupcakes in refrigerator.
Tips: You may substitute ½ cup whole-wheat pastry flour for ½ cup of the all-purpose flour if desired.
To make ¾ cup sour fat-free milk, place 2 teaspoons lemon juice or vinegar in a glass measuring cup. Add enough fat-free milk to measure ¾ cup total liquid; stir. Let stand for 5 minutes before using.
If using a sugar substitute in place of granulated sugar, choose Splenda(R) Sugar Blend for Baking or Sun Crystals(R) Granulated Blend. Follow package directions to use product amount equivalent to sugar amount called for. Nutrition per frosted cupcake with sugar substitute: same as below, except 192 cal., 23 g carb. Exchanges: ½ other carb. Carb Choices: 1½.