These lemon cupcakes are so moist and fluffy! They have the perfect texture and the taste is phenomenal. To achieve the perfect lemon flavor we use a full 3 tablespoons of lemon zest and fresh lemon juice in the cupcake batter. The end result is a fresh lemon flavored cupcake.
Preheat oven to 350°F. Line a cupcake pan with paper liners.
In a large bowl whisk the flour, baking powder, baking soda, and salt. Set aside.
In a medium sized bowl add the sugar and lemon zest. Use your hands to rub the lemon zest into the sugar. To the sugar add the warm melted butter, eggs, sour cream, buttermilk, and lemon juice. Whisk until the mixture is smooth.
Add the wet ingredients to the dry ingredients and mix until just combined and no flour streaks remain.
Portion the batter into the cupcake liners, filling about 2/3 to ¾ full. Bake for 16-18 minutes or until a toothpick inserted in the center comes out clean or with a few moist crumbs. The tops of the cupcakes should be springy when touched.
Let cupcakes cool in the pan for 5 minutes then transfer to a wire rack to cool completely.
Make the lemon buttercream: In the bowl of a stand mixer fitted with a paddle attachment cream the butter on medium speed until smooth, about 1 minute. Add the powdered sugar, lemon juice, heavy cream, lemon zest, and salt and mix on low until combined, then mix on medium speed for 2-3 minutes.
Add additional heavy cream if the frosting is too stiff, and if the mixture is too thin add powdered sugar a spoonful at a time. Transfer to a piping bag and frost the cooled cupcakes.
Notes
Store covered in the fridge for up to 3 days, but let come to room temperature before eating.