Velvety Chocolate Mousse Sauce

1. Combine Cocoa Powder, Sugar, and Milk

Combine the cocoa powder, sugar, and 1/4 cup (60 ml) of milk in a small, heavy saucepan. Stir these ingredients together until they form a thick, lump-free paste.

2. Whisk in Remaining Milk

Gradually whisk in the remaining milk, making sure to do this slowly to maintain the smooth texture. Place the saucepan over medium-high heat and bring the mixture to a simmer.

3. Add Butter and Salt

Once the mixture is simmering, whisk in the butter and a tiny pinch of kosher salt. Taste the sauce and adjust the sugar if needed to balance the flavors. Transfer the sauce to a medium bowl and let it cool completely, stirring often to prevent a skin from forming.

4. Whip Heavy Cream

While the sauce is cooling, whip the heavy cream to firm peaks using a handheld electric mixer in a medium bowl.

5. Fold Sauce into Whipped Cream

When the chocolate sauce has cooled to room temperature, fold one-fourth of it into the whipped cream using a rubber spatula. Once most of the sauce is mixed in and a few streaks remain, repeat the folding process with the remaining sauce in three more batches.