Ingredients
½cupwhole milk
½whole vanilla bean,or 1 bean
1½cupsall purpose flour,plus 2 tbsp
¼tspkosher salt
1¼tspbaking powder
¼cupsour cream
1½tspvanilla extract
½cupunsalted butter,(1 stick), room temperature
1cupsugar
1large egg
2egg whites
½cupunsalted butter,(1 stick), room temperature
1¼cupspowdered sugar
½vanilla bean,(or 1 tsp) of vanilla extract
Preparation
Preheat oven to 350 degrees and prepare the cupcake pan: Line a 12-cup muffin or cupcake tin with cupcake liners and set aside.
While the oven preheats, cut open and scrape out the seeds of a vanilla bean.
Place the seeds, empty bean, and milk in a small saucepan. Warm over medium heat for a few minutes until the milk is just starting to steam. Be careful not to boil or scald the milk.
Remove from heat and allow the milk to cool with the vanilla beans. After it cools, remove the bean pod. (Wash it and then place it out to dry so it can be used again.)
In one bowl whisk together the flour, baking powder, and salt.
In another bowl whisk together the vanilla-steeped milk, vanilla extract, and sour cream.
Beat the butter in the bowl of a stand mixer fitted with a beater attachment for about 3 minutes on medium speed, then add the sugar and beat for about 3 minutes until light and fluffy.
Add the egg and beat for 30 seconds. Add the egg whites, one at a time, beating for 30 seconds each. Scrape down the sides of the mixing bowl.
Add half the flour mixture to the batter and mix on low until combined. Then add all of the milk mixture and mix to combine.
Finally, add the remaining flour mixture and mix until just combined and there’s no more visible dry flour. Be careful not to over-mix.
Divide the batter evenly between the cupcake liners in the muffin tin. Bake at 350 degrees F for 18 to 20 minutes or until slightly golden brown.
Rotate the pan after 10 minutes to ensure even baking. Be sure to keep a close eye as these can get over-baked quickly.
Allow the cupcakes to cool for a few minutes in the pan, then carefully transfer them to a wire rack to cool completely.
Beat the butter for the frosting and slowly add in the powdered sugar. Scrape the seeds out of the vanilla bean (or vanilla extract if using) and beat in.
Frost each cupcake individually and serve. Cupcakes are best served the same day they are made, though will keep fairly well for a few days in an airtight container at room temperature.
