Allow the butter, buttermilk, and eggs to come to room temperature.
Preheat oven to 350 degrees F. Line cupcake/muffin pan with paper cupcake liners.
In a medium bowl, whisk together the flour, baking powder, and salt. Set aside.
In the bowl of an electric mixer, beat the sugar and butter until light and fluffy, about 2 minutes. Scrape down the sides of the bowl with a spatula as needed.
Add the egg, vanilla bakery emulsion, lemon bakery emulsion, lemon zest, and lemon juice, and beat 2 minutes more until fluffy.
Add the buttermilk and dry ingredients alternately, 1/3 at a time. Blend until well combined. End with the flour mixture. Scrape down sides of bowl as needed.
Divide the batter among 17 cupcake cups, filling each about 2/3 full. Do not overfill.
Bake at 350°F for 20-22 minutes, or until a toothpick inserted comes out clean. Let cool for 10 minutes before removing to a wire rack to cool completely.