Heat the oven. Preheat oven to 350 degrees.
Combine the dry ingredients. In a mixing bowl, whisk together flour, ginger, cinnamon, cloves, nutmeg, baking powder, baking soda and salt. Set aside.
Cream the butter and sugar. In the bowl of an electric stand mixer fitted with the paddle attachment, cream together sugar and butter until well combined, occasionally stopping and scraping down bowl.
Add the wet ingredients. Mix egg yolk and vanilla. Mix in molasses and 1 Tbsp milk.
Bring the dough together. With mixer set on low speed, slowly add in dry ingredients and mix until combined, while adding additional milk as needed just to bring dough together.
Roll the dough. Divide dough into two equal portions, then roll each portion out evenly to 1/4-inch thickness (into more of an oblong or rectangular shape so it will fit on a cookie sheet) between two sheets of parchment paper.
Chill and cut. Chill on a cookie sheet in freezer 10 - 20 minutes, or until firm, then cut into shapes using cookie cutters.
Transfer and bake. Remove from paper using a thin metal spatula or pastry scraper if needed, then transfer to parchment paper lined cookie sheet, spacing cookies about 1-inch apart, and bake in preheated oven 8 minutes or until slightly set.
Cool completely. Remove from oven and cool on baking sheet 2 minutes, then transfer to a wire rack to cool completely. Repeat process with remaining dough.
Prepare the icing. Add powdered sugar and meringue powder to the bowl of an electric stand mixer. Fit mixer with paddle attachment, add in 4 Tbsp water and the vanilla then mix on low speed until combined.
Adjust and whip the icing. Add more water to thin as needed and increase speed and whip mixture until it is glossy and thickens up. Tint with food coloring if desired. Transfer to piping bags fitted with tiny round tips.
Decorate the cookies. Decorate cookies with icing and add sprinkles if desired. Let icing set at room temperature and store in an airtight container.