Pretty much the basic formula is 1:2 softened butter to chocolate (2.5 for white or milk) with some glucose (corn syrup) and whatever flavoring you are using. The key difference is it is a water in fat emulsion, instead of a fat in water emulsion like a cream ganache. And i think that is whats giving it the wonderful texture. It's a bit trickier to make which is why I had shied away from the in the past, but totally worth the extra effort if this batch is any indication. The big key is in order to get it to set properly you MUST temper the chocolate and add it to the room temp butter. Here I the recipe I used adapted from Peter Grewelings Chocolates and Confections. I swapped out the dark rum for actual eggnog, because I don't care much for the taste of alcohol, and I wanted a really "eggnoggy" taste. 170g butter (77F) 40g Glucose syrup 1tsp ground nutmeg 1vanilla bean split and scraped 500g white chocolate, melted tempered and at 86F 40g eggnog (or rum) at about 86F so not to shock the chocolate, I warmed it ahead of time and steeped with about five whole cloves to adda little extra kick then strained I also thru in 1/4 tsp lorann eggnog flavor oil... I know that's blasphemy to purists, but I love the flavor of eggnog I wasn't piping right away so I mixed the butter, glucose, nutmeg, and vanilla with a hand whisk. then added the tempered chocolate. Mixed til smooth and streamed in the eggnog. Set up beautifully and so silky to taste.