Bring the 1/2 cup of heavy cream to a boil and remove it from the heat as soon as it starts to simmer.
Pour the hot cream over the chopped chocolate in a bowl, cover it, and let it sit for 5 minutes. Then, gently stir until it forms a smooth, shiny ganache. Allow it to cool for 10 minutes.
In another bowl, whisk the chilled heavy cream until it reaches stiff peaks, being careful not to overmix.
Gradually add the whipped cream to the ganache in 2-3 additions, gently folding between each addition. Be gentle to keep the air in. This will create a mousse-like chocolate cream.
Refrigerate the mixture for 20 minutes or until it reaches a pipeable consistency.