Vanilla Cupcakes with Swiss Meringue Buttercream

Step 1
Preheat the oven to 350 degrees F (175 degrees C). Line two 12-cup muffin tins with paper liners.

Step 2
Make the cupcakes: Mix flour, baking powder, and salt together in a medium bowl.

Step 3
Beat butter and sugar with an electric mixer in a large bowl until creamy. Add eggs, 1 at a time, followed by vanilla, beating well after each addition. Mix in flour mixture alternately with milk until smooth. Spoon batter into the prepared muffin cups, filling each 2/3 full.

Step 4
Bake in the preheated oven until a toothpick inserted into the center comes out clean, 15 to 23 minutes.

Step 5
Remove from the oven and cool in the tins for 5 minutes. Transfer cupcakes to a wire rack and let cool completely, about 20 minutes.

Step 6
While the cupcakes are cooling, make the buttercream: Bring a pan of water to a simmer. Combine sugar, egg whites, and salt in the bowl of a stand mixer. Place the bowl on top of the pan and whisk until sugar dissolves.

Step 7
Attach the bowl to the stand mixer and beat with a whisk attachment until mixture is cool and glossy and stiff peaks form. Add butter, a few tablespoons at a time, beating well after each addition. Add vanilla and mix until smooth.

Step 8
Spread buttercream onto cooled cupcakes.