• Prep the oven and pan. Preheat the oven to 350°F. Line a standard 12-cup muffin pan with paper liners.
• Combine the dry ingredients. In a medium bowl, whisk together the flour, ginger, cinnamon, cloves, allspice, and salt until evenly combined.
• Cream the butter and sugar. In a large bowl, beat the softened butter and granulated sugar with an electric mixer until light and fluffy, about 2–3 minutes.
• Add the molasses and egg. Beat in the molasses and egg until smooth and well combined.
• Combine the hot water and baking soda. In a heatproof measuring cup, carefully stir the baking soda into the boiling water until completely dissolved.
• Finish the batter. With the mixer on low, slowly add the hot water mixture to the molasses mixture. The mixture may look thin or slightly curdled; this is normal. Add the dry ingredients and mix on low just until combined. Do not overmix.
• Fill the cupcake liners. Divide the batter evenly among the 12 prepared liners, filling each about ⅔ full.
• Bake. Bake in the center of the oven for about 18--20 minutes, or until the tops spring back lightly when touched and a toothpick inserted in the center comes out with a few moist crumbs. The cupcakes will be fairly flat and may dip slightly in the center—this is normal.
• Cool completely. Let the cupcakes cool in the pan for 5 minutes, then transfer them to a wire rack to cool completely before frosting.

Make Frosting

• Beat the butter first. In a large bowl, beat the softened butter with an electric mixer until smooth and creamy, about 1 minute.
• Add the cream cheese. Add the softened cream cheese and beat on medium speed just until smooth and combined. Don’t overbeat, or the frosting can become too soft.
• Add the powdered sugar. With the mixer on low, gradually add the powdered sugar. Once incorporated, beat just until smooth.
• Add the flavorings. Beat in the vanilla, lemon zest, and lemon juice just until evenly combined. Avoid prolonged beating.
• Chill the frosting. Cover and refrigerate for 30 minutes, or until firm enough to spread or pipe. If it still feels too soft for piping, refrigerate it for another 10–15 minutes.
• Frost the cupcakes. Make sure the cupcakes are completely cool before frosting. Spread or pipe the frosting over the cupcakes, then garnish with chopped crystallized ginger and/or mini gingerbread cookies, if desired.