Pumpkin Spice Cupcakes with Orange Sour Cream Frosting

Heat oven to 350 °F. Line two 12-cup muffin tins with paper liners. In a medium bowl, whisk together the flour, ginger, baking powder, baking soda, salt and cloves. Using an electric mixer, beat 1 cup butter (2 sticks) and the granulated sugar in a large bowl until light and fluffy, about 3 minutes. Beat in the eggs one at a time. Beat in the pumpkin and the molasses (the mixture will look curdled). Reduce the mixer speed to low and gradually add the flour mixture, mixing just until incorporated. Divide the batter among the muffin cups (about 1/4 cup each) and bake until a wooden pick inserted in the center comes out clean, 20 to 25 minutes. Let cool for 5 minutes in the pan, then transfer to a wire rack to cool completely. Meanwhile, make the frosting: Using an electric mixer, beat the confectioners' sugar, sour cream and remaining 6 Tbsp butter in a large bowl until smooth. Increase the speed to medium-high and beat until fluffy, about 3 minutes. Stir in the orange zest. Refrigerate the frosting until stiff and spreadable, at least 1 hour. Frost the cupcakes just before serving.