Keep on whisking and incorporate salt, melted butter, honey or sweetener of choice then vanilla and buttermilk.
Whisk in flour. If we have an electric mixer, we can save time by throwing everything together and let the machine do the hard work but otherwise follow the steps to easily incorporate all the ingredients.
If buttermilk is used, now it is the time to add the baking powder and the optional baking soda then whisk it in as fast as we can. Adding baking powder earlier will result reaction of the baking powder with the acid of the buttermilk which would ruin the fluffiness of our cake.
Quickly spoon the muffin forms up until about ¾ height.
Place the vanilla muffins into the middle rack of a 360°F / 180°C preheated oven until the top turns golden brown which should happen when a kitchen thermometer registers 210°F / 99°C, about 40 minutes.
Vanilla German Buttercream
Warm the milk up in a pot on medium heat until it starts to bubble gently.
In a medium bowl, whisk the egg yolks for about a minute, until light yellow and increased in volume. Whisk in the cornstarch, vanilla extract, sweetener and gradually about ½ cup of the hot milk.
Slowly pour all of the egg yolk mixture into the scalding milk while stirring vigorously until the mixture seems completely dissolved. Keep warm and continuously stir until the custard thickens.
While letting the custard cool to room temperature, cream the butter. Whisk the creamed butter and cooled custard together.
Vanilla Cupcake Assembly
Possibly with a pastry bag or a similar fancy equipment that is capable of making gorgeous lines from cream, place some cream on top of the muffins.