Prep: Preheat your oven to 375ºF. Line two 12-cup muffin pans with 6 liners each, alternating cups.
Mix dry ingredients together: In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside.
Cream butter and sugar: In a large bowl, beat the butter and sugar together on medium-high speed until light and fluffy (2-3 minutes)
Add eggs and flavorings: Beat in the eggs one at a time, mixing well after each. Add the lemon zest, lemon juice, and vanilla extract. Beat until combined (it may look slightly curdled — that’s normal!)
Alternate dry and buttermilk: Add the dry ingredients in three additions, alternating with the buttermilk and starting and ending with the dry ingredients. Mix on low speed until just combined — don’t over mix!
Fill and bake: Divide the batter evenly among the 12 liners, filling each about ⅔ full. Bake for 5 minutes at 375ºF, and then lower the temperature to 350ºF and bake for another 13-16 minutes, or until a toothpick inserted into the center comes out clean.
Cool: Let cupcakes cool in the pan for5 minutes, then transfer to a wire rack to cool completely before frosting
