Step #1 Heat oven to 350°F Line muffin c (2-1/2 inches in diameter) with paper bake c.
Step #2 Stir together flour, baking powder, baking soda & salt in medium bowl; stir in the yogurt, granulated sugar, cocoa, milk & vanilla just until mixd.
Step #3 Do not beat.
Step #4 Fill muffin c 2/3 full with batter.
Step #5 Bake 15 to 20 mins or until wooden pick inserted in center comes out clean.
Step #6 Cool slightly in pan on wire rack.
Step #7 Remove from pans.
Step #8 Sprinkle top powdered sugar over tops of muffins, if desired.
Step #9 Serve warm.
Step #10 Store, covered, at about room temp or freeze in airtight container for longer storage.