Chocolate Mocha Cake with Vanilla-Espresso Swiss Meringue Buttercream

I have a new obsession: Swiss Meringue buttercream!  I am so utterly pleased with it and don't know why it has taken me this long to discover it.  Swiss meringue is nothing new, just a new discovery to me. So much easier and faster to make than Italian Meringue buttercream, which is what I have been using for all my wedding cakes.  Most of all I think you will find it is very user friendly, even if you don't really know what you're doing.

The differences between the Swiss buttercream and the Italian version are mostly in the cooking method.  The Italian version requires you boil sugar and water to 238 degrees, soft ball stage.  While this is not really a problem, it does take considerably longer to make.  I found the Italian version is fluffier at the start and has about 20% more butter in it, but in the end I can't imagine the difference being monumental.  The Swiss version has a larger egg white to butter ratio and delightfully comes together in 10 minutes or less.  Temperature is everything in both versions- they both tend to look curdled while beating and can either be too soft or too stiff, all of which can be easily corrected by continuing to beat.  I added instant espresso powder to the basic vanilla version, if you omit it, you can then flavor it with anything you'd like.  I have not made a chocolate version, but I am assuming it would work well also.  Lastly, make sure the mixer bowl and whip are both clean of any greasy residue before beginning.

2- 9" chocolate cake layers- recipe found here

1 recipe Swiss Vanilla-Espresso Buttercream (makes approximately 5 cups)

Swiss Vanilla-Espresso Buttercream

6 egg whites 

1 cup granulated sugar (200 grams)

340 grams unsalted butter (3 sticks), at room temperature

1 vanilla bean, scraped

1 teaspoon vanilla extract

3 teaspoons instant espresso powder dissolved in 2 teaspoons of boiling water

1. In the bowl of an electric mixer combine sugar and egg whites.  Place over a pot of simmering (not boiling) water and whisk until mixture reaches 160 F or without a thermometer until all sugar is dissolved and the egg whites are hot. 

2. With the whisk attachment beat meringue on medium-high speed until thick and glossy. (tip: after adding sugar to egg whites, you cannot over beat them). 

3. Slowly add butter a little at a time until well incorporated.  The mixture may look curdled at this point (I promise it will pull back together), continue to whip until light and fluffy.  Add flavorings and beat until well combined.