'a muffin pan with 12 (1/2-cup) cups; 12 paper liners'
Put oven rack in middle position and preheat oven to 350°F
Line muffin cups with liners
Pulse crystallized ginger in food processor until finely ground, then add flour, ground ginger, cinnamon, zest, salt, baking soda, and baking powder and pulse until combined
Whisk together zucchini, oil, honey, eggs, and vanilla in a medium bowl, then stir in flour mixture until just combined
Divide batter among muffin cups and bake until golden and a wooden pick or skewer inserted in center of a cupcake comes out clean, 20 to 24 minutes
Cool in pan on a rack 10 minutes
Remove cupcakes from pan and cool completely, 1 hour
Beat together frosting ingredients with an electric mixer at high speed until combined well and fluffy, 3 to 5 minutes