Chris is “sick and tired of people not making chocolate mousse.” Luckily, he has just the recipe to fix that: our Salted Butter Caramel-Chocolate Mousse. With butter-and-cream richness, bittersweet notes from the chocolate and caramel, and sea salt to cut through the sugar, this simple six-ingredient dessert from “My Paris Kitchen” by David Lebovitz is far greater than the sum of its parts.

You don’t need water when making caramel

The first step to making any caramel is melting the sugar. “A lot of recipes will say, ‘two parts sugar; one part water,’” said Chris. But we have an easier method: Spread the sugar out in a skillet or a saucepan. “That way, you can see the color change better.” It’s also faster, because you don’t have to wait for the water to boil off.

As the sugar begins to melt at the edges, use a silicone spatula to push the liquefied sugar toward the center. Continue to cook, stirring gently, until all the sugar is melted and caramelizes to a deep amber color and begins to smoke. “You really want to get a darker color, because caramel has a slight bitterness to it, which makes it so delicious. Otherwise it’s going to be just full-on sweet.”

Once you reach that dark and golden sweet spot, remove the pan from the heat and add the cream. The colder temperature of the dairy will cause the caramelized sugar to seize up, but don’t panic. Just keep stirring. “If you need to put it back on the heat, you can.”

The right chocolate isn’t too dark

“You shouldn’t get 80% or 90% cacao chocolate, which means the sugar content is very low. It’s nasty stuff.” Instead, aim somewhere in the 60-70% range. Guittard is a good brand. Add the chopped chocolate into the caramel mixture, stirring until melted and smooth, then set aside to cool.

Sugar brings stability to egg whites

Whipped egg whites give this mousse its lofty height and airy texture. Though the recipe doesn’t call for it, Chris likes to add a little sugar to the frothy whites. The granulated sucrose draws moisture from the whites, creating a thick, viscous syrup that slows drainage from the bubble walls (aka “weeping”). This stabilized foam is more difficult to over-whip and less likely to deflate when stirred into the chocolate base.

Aim for stiff peaks

Soft peaks are the goal for egg whites that are destined for cake, as it makes them easier to incorporate them into the batter without knocking the air out of the foam. But this is not a cake. There aren’t any heat-activated chemical leaveners; all of the volume comes from the whipped whites. Just-stiff peaks provide the best texture.

If you’re worried about over-whipping, you can start them with a stand mixer and finish them by hand. “With that stand mixer, if you did it three seconds too long you can end up over-beating them.”

Add the whites in stages

“This is the typical problem with chocolate. You have a really thick batter.” To best incorporate the delicate whites into the rich chocolate base, we add them in stages. The first third of the the foam lightens the texture of the chocolate, making it easier to fold in the remaining two-thirds.

Chill , salt and serve

Once the egg whites are folded in, all you have to do is portion the mousse into cups (or pile it all into one big serving bowl). Cover and refrigerate for at least 8 hours or up to 24 hours. Garnish with flaky salt just before serving.

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Claire Lower

Claire Lower is the Digital Editor for Christopher Kimball’s Milk Street, with over a decade of experience as a food writer and recipe developer. Claire began writing about food (and drinks) during the blogging boom in the late 2000s, eventually leaving her job as a lab technician to pursue writing full-time. After freelancing for publications such as Serious Eats, Yahoo Food, xoJane and Cherry Bombe Magazine, she eventually landed at Lifehacker, where she served as the Senior Food Editor for nearly eight years. Claire lives in Portland, Oregon with a very friendly dog and very mean cat. When not in the kitchen (or at her laptop), you can find her deadlifting at the gym, fly fishing or trying to master figure drawing at her local art studio.