Pre-heat the oven to 375°F.
Divide the prepared cake batter into nonstick muffin tins and bake for 20 minutes. The batter will make 8-10 muffins, depending on the size of your tin. Turn the muffins out of the tins to quick-cool.
Beat the cream cheese, pumpkin, nutmeg, orange zest and vanilla with a hand mixer at medium speed. Beat in the sugar until the frosting is fluffy. Frost the cupcakes and top with the crystalized ginger.