1 cup unsalted butter, softened to room temperature (for frosting)
4 cups confectioners’ sugar, plus more as needed (for frosting)
1/4 cup heavy cream, half-and-half, or whole milk, at room temperature (for frosting)
2 teaspoons pure vanilla extract (for frosting)
Salt, to taste (for frosting)
Optional for garnish: lemon slices and/or mint sprigs
Instructions
Preheat the oven to 350°F (177°C). Line a 12-cup muffin pan with cupcake liners.
Whisk together the flour, baking powder, and salt in a large bowl. Set this dry mix aside.
Beat the softened butter, granulated sugar, and lemon zest together until creamy, about 3 minutes. Add the eggs and vanilla extract, mixing until well combined.
Gradually add the dry ingredients to the butter mixture, alternating with the milk and lemon juice, mixing until just combined.
Fill the prepared cupcake liners with the batter, about 2/3 full, and bake for 18 to 21 minutes, or until a toothpick inserted in the center comes out clean.
Allow the cupcakes to cool completely in the pan for 5 minutes, then transfer them to a wire rack to cool completely.
For the frosting, beat the softened butter until creamy. Gradually add the confectioners’ sugar, mixing until smooth. Add the cream or milk and vanilla extract, adjusting the consistency as needed.
Frost the cooled cupcakes with the buttercream frosting and garnish with lemon slices or mint sprigs if desired.
Notes
Use room temperature ingredients for the best results. Store leftovers in the refrigerator for up to 4 days.