White Chocolate-Vanilla Bean Buttercream

Make the White Chocolate Custard Base

Combine the white chocolate and butter in a large bowl set over hot, not simmering, water. Melt the mixture, stirring often until smooth and creamy. (Don’t let the bottom of the container touch the water.)

Whisk the eggs lightly to break them up and then whisk them into the melted white chocolate mixture. Contin