Apple-Walnut Donuts

Preheat oven to 350ºF. Coat a standard-size (3 1/2-inch) doughnut pan* or twelve 2 1/2-inch muffin cups with cooking spray. In a bowl combine the next four ingredients (through salt). In another bowl combine the next five ingredients (through vanilla); whisk until smooth. Add yogurt mixture, apple, and walnuts to flour mixture; stir until combined.

Spoon batter into a large resealable plastic bag. Using scissors, cut off a corner; squeeze batter into prepared pan, filling each cup about two-thirds full. Smooth tops.

Bake about 15 minutes or until doughnuts are nearly firm when lightly pressed. Cool in pan on a wire rack 3 minutes. Turn doughnuts out of pan onto wire rack; cool completely.

In a bowl stir together ground walnuts, sugar, and 1/2 teaspoon cinnamon. For icing, in another bowl stir together powdered sugar and milk until smooth. Dip cooled doughnuts into icing, allowing excess icing to drip back into bowl. Transfer to a wire rack covered in foil. Sprinkle with ground walnut mixture. Let stand until icing is set.