When we first spied this Italian mousse in a restaurant outside Milan, we thought it was zabaione, the rich, Marsala-soaked custard that can get a bit of a bad rap in the dessert world. I get it. Zabaione can swing heavy and boozy if it isn’t made well. But the elegance of this mousse—made from a surprise ingredient—belies its simple method.

Made with just five ingredients—sugar, eggs, dark rum, cocoa powder and mascarpone (Italian cream cheese)—this crema al mascarpone comes together in just a few minutes. Unlike a zabaione, you don’t have to stand over a double boiler whisking egg yolks. The dish gets its light, airy texture from whipped uncooked egg whites, which makes it closer to a French mousse than a custard.

Get all of your ingredients to room temperature

While the mousse itself takes 20 minutes to come together, there’s a little inactive prep time: Put your mascarpone and eggs on the counter a few hours before you’re ready to make dessert. Room-temperature ingredients, particularly eggs and dairy, emulsify easier and incorporate air better.

Here’s the pro tip you want: Do separate your eggs right out of the fridge, then let the yolks and egg whites warm up in different dishes. Cold eggs separate much more cleanly, and when when whipping egg whites (more on that in a minute), you want to make sure there isn’t a trace of fat in your mixture or on your tools. Fat can inhibit how fluffy and light the whites get.

Fresh eggs make a difference

This isn’t the recipe to use old, back-of-the-fridge eggs for. Like anything, eggs age! When they’re fresh, they whip more stably into a billowy foam and hold their shape better, thanks to the thicker, more acidic nature of the whites. Acids stabilize whipped egg whites; think about meringue recipes that suggest a pinch of cream of tartar or lemon juice to keep lofty and tall. Older egg whites are watery and more alkaline, and while they whip faster, they’ve lost some of their ability to trap air and form a stable, voluminous foam.

Given that the egg whites are responsible for the lightness of the dish, fresh eggs are worth seeking out.

Clean your whipping bowl

Take an extra minute to make your your whipping tools are squeaky clean before you start. When I whip egg whites, either with a stand mixer or hand mixer (you can use the latter here), I wipe out my bowl and the tines of my whisk attachments with a paper towel dunked in vinegar. Follow up with a damp paper towel to remove any residual vinegar and let the tools dry. Any fat in the bowl will keep the egg whites from whipping correctly, so this extra step provides insurance—and prevents wasted eggs.

Whip the eggs only to soft peaks here. They should be opaque and droopy when you lift your whisk out of the bowl, the peaks folding back on themselves immediately.

Don’t overmix your mascarpone

Even though mascarpone is casually referred to as Italian cream cheese, it’s a little more delicate to handle than a block of Philadelphia. Mascarpone can break if overmixed, and grainy cheese may cause the whole dessert to separate. Use a very light touch as you fold your egg whites into the room temperature mascarpone and egg yolks. Do it in batches and stop as soon as no streaks remain.

The finishing touches

A hint of dark rum is one of the dessert’s nods to zabaione, which uses sweet wine or Marsala. Dark rum is smoky-sweet and layered with notes of caramel and brown sugar. (I would not substitute spiced or light rum here.) The dark rum and a light dusting of cocoa add a final flourish of depth and flavor to the dessert.

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Priyanka Shahane