Preheat oven to 350°F. Line 2 muffin tins with cupcake liners, then set aside.

In a medium bowl, whisk together flour, baking powder, and salt. Set bowl aside.

Using a stand mixer (or hand mixer + large bowl), add sugar, butter, and cream cheese. Beat on medium speed until fluffy, about 2-3 minutes.

Reduce mixer speed to low and add on eggs, one at a time, blending thoroughly inbetween.

Keeping speed on low, add Limoncello, then blend for 1 minute.

Keeping speed on low, add half of dry ingredients to wet ingredients, then mix for 10-20 seconds. Pour in milk, then mix for 10-20 seconds more. Add remaining dry ingredients, mix another 10-20 seconds, then add lemon juice and lemon zest. Continue mixing until batter is just combined, being careful not to overmix.

Pour cupcake batter into prepared muffin tin, filling cavities about ¾ full.

Bake for 20 minutes or until tester toothpick comes out clean.

Let cupcakes cool in tin for 5 minutes, then transfer to a wire cooling rack to cool completely. Note: If using cake flour, cupcakes will "shrink" slightly while cooling; this is normal.

Using a stand mixer (or hand mixer + large bowl), whip butter and cream cheese on high speed until fluffy, about 5-7 minutes.

Drop speed to low and slowly add sugar, mixing thoroughly in between.

Keeping speed on low, add Limoncello and whip until frosting is smooth, about another 2-4 minutes. Taste test frosting; this frosting is very forgiving and easy to balance to your tastes. You can add up to 6 tablespoons of Limoncello (total) or up to 5 cups of powdered sugar (total) to get flavor and consistency you'd like.

When ready to decorate, fill a pastry bag with prepared Limoncello cream cheese frosting and a piping tip of your choice.

Frost each cupcake in a decorative pattern, then dust top with sprinkles or other decorations, like a lemon twist.

Serve as desired.