Protein-butter cream with Italian meringue

Ingredients:

• Protein of 4 large eggs
• 1.5 cups of sugar
• A pinch of coarse salt
• 450 g butter at room temperature, cut into 2.5 cm pieces.
• 1 tsp vanilla extract
• Special equipment: syrup thermometer

Preparation:

1. Place the egg whites and 1/3 cup sugar in the bowl of a stand mixer fitted with a whisk attachment. Beat on medium-high speed until soft peaks form.
2. Meanwhile, in a medium saucepan, combine the remaining sugar and 1/3 cup water over medium heat. Attach a syrup thermometer to the side of the pan and cook, without stirring, until the syrup reaches the soft-ball stage (115°C).
3. The whipped egg whites and syrup should be ready at about the same time. If one component is ready before the other, you can remove the pan from the stove or pause the whipping for a few minutes.
4. While whisking the egg whites at medium-high speed, slowly pour in the hot syrup, directing it between the sides of the bowl and the beaters. Continue whisking until the bottom of the bowl and the mixture have cooled, 10-15 minutes. At this point, the mixture should be thick and hold stiff peaks. Stir in the salt. You now have Italian meringue.
5. Beating on medium-high speed, add the butter a few pieces at a time. The cream may seem to thin out as you add the butter, but it will thicken again to stiff peaks once all the butter is incorporated. Stir in the vanilla extract. If the cream is still too thin, beat on high speed until it thickens.
6. Use the cream immediately or refrigerate it overnight in an airtight container. You may need to beat the cream slightly before use to make it smooth.