Try this Chocolate Nutella Ganache recipe, or contribute your own.
The ingredient list fails to mention that chopping the semi-sweet chocolate into uniform quarter-inch pieces dictates whether the mixture emulsifies properly. When hot cream hits the bowl, residual heat must melt both the chocolate and the butter without seizing the cocoa solids. Heat the heavy cream until bubbles form around the edge of the saucepan at roughly 180 degrees Fahrenheit, just below a rolling boil, ensuring sufficient thermal energy to melt the fats.
Many cooks ruin emulsions by introducing moisture or using chocolate chips coated in stabilizers that prevent smooth melting. Avoid standard chocolate chips entirely because their paraffin additives interfere with the velvety finish required for a proper spreadable consistency. Whisking too aggressively from the start incorporates excess air bubbles that ruin the glossy appearance of the finished emulsion.
Allowing the mixture to rest undisturbed for thirty minutes at room temperature achieves the ideal viscosity for piping or spreading. Storing leftovers in a sealed container in the refrigerator preserves usability for up to five days, provided the batch returns to room temperature and receives a vigorous re-whisking before application.