I’ve used that before for making ganache, but our store doesn’t carry it anymore so I make do with G&B 85%. Use the unsweetened for the cocoa mass (chocolate liquor) percentage in a ganache or cake recipe (doesn’t work for buttercreams). That is, if a recipe calls for 100g of 60% chocolate, use .60 * 100 = 60g of the unsweetened chocolate, plus 40g of sugar. For ganache, add the sugar to the cream, heat and dissolve before adding it to the chocolate. For cakes, add the sugar with the rest of the sugar in the recipe.