Billy's Vanilla Vanilla Cupcakes with Swiss Meringue Buttercream

First, may I make a recommendation? These cupcakes + frosting take a while to make. Listen to The DFA Remixes: Chapter Two to keep you going!

Out of the three vanilla cupcake recipes I've tried (Amy Sedaris', a recipe from Nosh With Me, and Billy Reece's recipe) this cupcake has the best flavor, although it's hard to judge the flavor of Amy Sedaris' recipe because I made it with 100 year old flour. Anyways, I'll be using this recipe for yellow/vanilla cake from now on. I asked my dad to tell me one thing that could be better. He said I need to work on making the cake as soft as a box mix cake. Enough about the cake, let's talk about the best part! I topped each cupcake with Swiss Meringue Buttercream, because everyone says it's a less sweet, more fluffy alternative to buttercream. THEY ARE RIGHT! SMBC is my new go-to frosting. I usually am not a fan of regular buttercream (butter, confectioners sugar, vanilla, milk), but this frosting I could've eaten by the spoonful. It was well worth the extra 10 minutes to make this!

Billy Reece's vanilla cupcake recipe (halved, makes 12 cupcakes):

3/4 cup + 2 tablespoons cake flour
1/2 cup + 2 tablespoons ap flour
1 cup sugar
1 1/2 teaspoons baking powder
1/2 teaspoon salt
1/2 cup unsalted butter
2 eggs
1/2 cup milk
1/2 teaspoon vanilla

Preheat oven to 325 degrees. Line cupcake pans with paper liners; set aside.
In the bowl of an electric mixer fitted with the paddle attachment, combine flours, sugar, baking powder, and salt; mix on low speed until combined.
Add butter, mixing until just coated with flour.
In a large measuring cup, whisk together eggs, milk, and vanilla.
With mixer on medium speed, add wet ingredients in 3 parts, scraping down sides of bowl before each addition; beat until ingredients are incorporated but do not overbeat.
Divide batter evenly among liners, filling about 2/3 full. Bake, rotating pan halfway through, until a cake tester inserted in the center comes out clean, 17 to 20 minutes. Transfer to a wire rack to cool completely.
Martha Stewart's Swiss Meringue Buttercream recipe (makes 4 cups):

4 large egg whites
1 1/4 cups sugar
1 1/2 cups unsalted butter, (3 sticks), softened, cut into tablespoons
2 1/2 teaspoons pure vanilla extract

Put egg whites and sugar in the heatproof bowl of an electric mixer set over a pan of simmering water. Whisking constantly, cook until sugar has dissolved and mixture is warm (about 160 degrees.
Attach bowl to a mixer fitted with the whisk attachment. Beat egg white mixture on high speed until it forms stiff (but not dry) peaks.
Continue beating until fluffy and cooled, about 6 minutes.
Switch to the paddle attachment. With mixer on medium-low, add butter several tablespoons at a time, beating well after each addition. (If frosting appears to separate after all butter has been added, beat on medium-high speed until smooth again, 3 to 5 minutes more.)
I thought it was ruined when it looked like this, but don't worry. Just continue whipping it. It will come together and be a dream come true! Beat in vanilla. Reduce speed to low; beat 2 minutes to eliminate air bubbles. Stir with a rubber spatula until smooth.

I think it would've been better with 2 or 2 1/2 sticks of butter instead of 3. I took half out of the bowl to leave as vanilla, and to the half still in the bowl I added 2/3 cups melted (and cooled) semi-sweet chocolate chips and about 3 tablespoons unsweetened cocoa powder. Mix on low speed until combined. I'd advise using less sugar in the beginning stage when turning this into a chocolate frosting because the semi-sweet chocolate adds a lot of sweetness.