Add the ruby chocolate into a glass bowl and microwave for 30 seconds. Stir, then microwave for another 30 seconds. Stir until all the ruby chocolate is melted and there are no lumps. Alternatively, you can melt the ruby chocolate using a double boiler. Set aside to cool slightly.
In the bowl of a stand mixer fitted with a paddle attachment, beat the butter on high until light and fluffy, about 4 minutes. Turn the mixer to low, add the powdered sugar, and mix until well combined. Scrape down the bowl and paddle, give the melted ruby chocolate a few stirs and make sure it’s not hot enough to melt the butter (if it is still too hot, wait a few minutes before adding!), then add it in. Turn the mixer to medium speed and beat for 2 minutes, until the mixture is smooth. Add the vanilla, heavy whipping cream, and salt and beat for another minute on medium.
