Super Firm Chocolate Ganache Filling

In a microwavable bowl, stirring with a silicone spatula every 15 seconds (or in the top of a double boiler set over hot, not simmering, water, stirring often—do not let the bottom of the container touch the water), heat the chocolate until almost completely melted.

Remove the chocolate from the heat source and stir until fully melted.

Pour the cream on top of the chocolate and