White Chocolate Buttercream
2 cups water
4 cups granulated sugar
about 2T cornstarch (note: the original recipe called for 3/4 cup, but when I did that, it just turned to a big gummy lump - I remade and just made a thick gel with the water/cornstarch mix)
2 pounds White Chocolate Candy Melts, Merckens or Genuine White Chocolate (Real chocolate will need to be tempered. I use Merckens.)
3 pounds butter (1 pound salted, 2 lbs unsalted), cold & cubed
¼ cup White Crème de Cacao (optional & alcoholic!)
2T vanilla extract
*This recipe can be halved with good results. You can use any color/flavor candy melts or chocolate. You can color, but it is advised to use candy coloring because of the chocolate content.
Mix sugar with 1 ½ cups water. Mix ½ cup water with cornstarch. Bring sugar water to boil on high heat. When your mixture boils, add some to the cornstarch mixture to temper it, then add the cornstarch to the sugar. Bring to a quick boil, then turn as low as possible. Simmer for 5 minutes. Meanwhile, put chocolate into a heat resistant bowl. (Break up chocolate if not in small pieces already.) Pour mixture over the chocolate and allow it to melt, stirring occasionally to prevent chunks. Cool to room temp, then add crème de cacao & vanilla. Strain into your mixer bowl and whisk in your butter, a few chunks at a time allowing them time to incorporate. If it appears to be runny (your emulsion broke) just keep mixing or put in fridge to chill and then rewhisk. You can also cool both melted chocolate, sugar/cornstarch mixture, and soften butter and incorporate in the same order without the time to cool or wait for the butter to work in.
If you refrigerate this icing it will set up ROCK HARD. You can then use a dough scraper to smooth any bumps or fill in any dips. At room temperature, it has a whipped cream consistency. I have used it under fondant w/o issue many times. In fact, this is the only way I've been able to get sharp edges and corners so far.