准备

Make the cupcakes

• Position a rack in the center of the oven and heat the oven to 350°F. Line 12 regular-size (2-3⁄4 inch diameter) muffin cups with paper or foil liners. Sift together the flour, ginger, baking powder, cinnamon, salt, and cloves in a medium bowl.
• 在装有桨叶附件的立式搅拌机中，以中等速度打败黄油和糖，直到蓬松而浅色，大约2分钟。每次添加后一次跳动一次，每次均匀地跳动。停止根据需要刮下碗和搅拌器。加入糖蜜并跳得光滑。（如果您看到非常小的凝乳，没关系。）
• 将一半的面粉混合物加入糖混合物中，并以低速混合直至混合。加入牛奶，混合直至混合。加入剩余的面粉混合物，并以低速混合直至混合。
• Portion the batter evenly among the prepared muffin cups. Bake until a toothpick inserted in the center comes out clean, about 18 to 20 minutes. Let the cupcakes cool on a wire rack for 15 minutes. Carefully remove the cupcakes from the pan and set them on the wire rack to cool completely.

Make the buttercream

• In a stand mixer fitted with the whisk attachment, whip the eggs on high speed until pale, fluffy, and greatly increased in volume, about 12 minutes.
• Meanwhile, put the sugar and 1/4 cup water in a 2- to 3-quart saucepan and attach a candy thermometer to the side. Heat the mixture over medium-high heat, swirling to dissolve the sugar, until it reaches 235°F, about 4 minutes. Transfer to a heatproof measuring cup. Turn the mixer to low and slowly pour the sugar syrup down the side of the bowl. Increase the speed to medium and beat until no longer warm when you touch the side of the bowl, about 10 minutes. The mixture should be very thick and light yellow in color.
• 逐步添加但ter, in pieces, until it is all incorporated. It’s OK if the eggs lose some volume. Add the rum, vanilla, nutmeg, and salt and beat on high speed until smooth, about 2 to 3 minutes more.

组装纸杯蛋糕

• Transfer the buttercream to a large pastry bag fitted with a large star tip. Pipe a generous spiral of buttercream onto each cupcake. Grate a generous amount of nutmeg over the cupcakes. The cupcakes will keep at room temperature in an airtight container for up to 3 days.