To make meringue buttercream, you’ll need to prepare Italian meringue as in the previous recipe and refrigerate it for 15 minutes.
Meanwhile, melt the chocolate in a bowl by microwaving until mostly melted, then set aside to cool down a bit
Gradually add butter cubes to the meringue bowl while mixing on a medium-high speed beating to prepare the buttercream. This should take about 5 to 10 minutes.
Gradually add the melted but not hot chocolate to the buttercream while mixing.
Gradually add the melted but not hot chocolate to the buttercream while mixing.
Dissolve the vanilla extract with the instant coffee and pour them over the frosting.
Mix all the ingredients on a medium to high speed until they have a homogenous stiff mixture of buttercream frosting.
When the mixture is ready, transfer it to a piping bag for frosting.