These are very good and make a great snack as well as a dessert.
3 egg whites - large, at room temperature, a pinch of cream of tartar, a pinch of salt, 1/2 cup + 1 Tbs. sugar, 1/4 cup Nutella
Preheat the oven to 300 degrees. Put the oven rack in the bottom third of the oven, and the other rack in the top third. Line 2 baking sheets with parchment paper and set aside. Set up a double boiler and put Nutella in the top of double boiler. Warm the Nutella and set aside, while you make the meringue, let the Nutella cool. Fit a stand mixer with the whisk attachment and put egg whites in the bowl. Beat on medium high until they are completely foamy. Add cream of tartar and salt, and continue whipping until soft peaks form. Increase speed to high and begin adding sugar slowly. Once all the sugar is in the meringue should be very thick (almost stiff.) Add all the Nutella, and gently fold (with a rubber spatula). Don't overmix - you want a swirled effect. Drop the meringue onto prepared sheets in large dollops. Bake for 10 minutes. After 10 minutes immediately lower the temperature to 200 degrees and rotate the pans. Bake for 1 hour. After 1 hour, check the meringues, if they are completely dried out, turn the oven off, and leave them in the oven for a few hours to cool with the oven. If they still look a bit "wet", then continue baking for another 20 minutes or so. Either way, turn the oven off and leave the meringues in for a few hours. When you remove the meringues they should be completely dry and cool and will sound hollow when you tap the bottom.