Shelf Stable "Ganache"
You could make a ganache type filling if you used water, cocoa powder,chocolate chips, butter, and icing sugar. Adding all but the chocolate chips in a saucepan will create a chocolate like sauce. Thick and with body. Once everything has melted,and blended smoothly together, you add the chocolate chips with the heat off. let the residual heat melt them the rest of the way. Once cooled it can be sandwiched between cookies, cake topping, cupcake "frosting", eclair icing. It is a shelf stable "ganache" like filling I like to use. In terms of quantity, I use 1 Lb. butter, 4 cups icing sugar, 1 cup water, 1 cup cocoa powder, 2 cups chocolate chips. This is a very rough recipe as I do most of my pastry making/baking by feel. *Note...The more chips you add, the thicker the end results.