This dulce de leche mousse is creamy and rich, light and airy, with a deep milk caramel flavor that melts in your mouth. Piped into glasses and topped with a sprinkle of flaky sea salt, this mousse is a special treat. This recipe uses easy homemade dulce de leche made from canned sweetened condensed milkfor a decadent dessert.
Place saucepan with dulce de leche mixture over medium low heat. Add milk and starch mixture, whisking to blend it all together. Continue to stir while gradually heating the mixture, at least 5 minutes. Don't walk away! If you have a thermometer, you'll be heating the mixture to about 175-180 degrees Fahrenheit. and then letting it bubble while you continue to stir the mixture for 90 seconds. This step neutralizes a starch-eating enzyme in the eggs, which will allow the pastry cream to remain set.
You should begin to feel the mixture pull on the whisk and create resistance as it begins to thicken. Once the mixture reaches the appropriate heat, it will begin to bubble and thicken very quickly. Continue to stir for 90 seconds while the mixture bubbles.
Immediately remove pastry cream from heat and strain through a mesh sieve into a heat proof bowl or dish. Spread it out to cool. Press plastic wrap onto the surface of the pastry cream to prevent a skin from forming. Place in the fridge to fully chill, for a minimum of 3 hours.
Begin this step once pastry cream fully chilled. To the bowl of a stand mixer fitted with the whisk attachment, add the heavy cream. Beat the cream on medium speed just until soft peaks form (when lifting the whisk out of the cream, a peak will form, but droop back downwards and begin to disappear back into the mixture).
125 mL (½ cup) heavy cream, refrigerated
Remove the pastry cream from the fridge and gently stir it with a spatula to loosen it up a bit. Place it in a large, wide bowl (best for the folding action needed to incorporate the whipped cream and egg whites). Scoop ⅓ of the whipped cream into the bowl and use a spatula to gently fold it into the pastry cream until only a few streaks remain. Add the remainder of the whipped cream and gently fold in using the minimum amount of strokes necessary. A few streaks are ok.
Wash your bowl and whisk well with soap and water to remove all traces of grease from the heavy cream. Place them back on your stand mixer. Next, add your egg whites to the bowl. Beat the egg whites on medium speed until slightly foamy. If using, add cream of tartar. Continue beating on medium speed until egg whites have turned white, cloudy and reached soft peak stage (When lifting the whisk out of the egg whites, a peak will form, but droop back downwards and begin to disappear back into the mixture).
2 large egg whites (approximately 66 grams), ¼ teaspoon Cream of Tartar
Scoop ⅓ of the egg whites into the bowl and use a spatula to gently fold it into the dulce de leche mixture until only a few streaks remain. Add the remainder of the egg whites and gently fold in using the minimum amount of strokes necessary.
You can either use a piping bag to pipe the mousse into cups, or scoop it into the cups with a spoon. For the piped mousse: place a jumbo star tip (I use Ateco 869) into a 16" (40cm) piping bag. Scoop the mousse into the piping bag and twist the top closed. Holding the bag vertically, pipe the mousse to fill each glass in one continuous circular motion, finishing with a decorative swirl on top. Divide the mousse evenly between the four glasses.
Chill in the refrigerator until ready to serve. (Cover if not serving within an hour or two). If desired, sprinkle with chocolate shavings and/or flaky sea salt before serving.