In a medium saucepan, combine milk, cream, and 1/2 cup sugar. Cook on medium-low heat, stirring constantly, until sugar is dissolved.

In a medium bowl, combine egg yolks and 1/4 cup sugar. Using a hand-held mixer or stand mixer, blend yolks and sugar until thick, pale, and fluffy, about 3 minutes.

Temper the egg yolks:  take about half a cup of the hot milk/cream and drizzle it, whisking constantly, into the egg/sugar mixture (this helps to bring the temperatures of the two mixtures closer together so the eggs won’t scramble when added to the milk). Once incorporated, slowly whisk the eggs and milk into the saucepan. Continue to cook for about 5 more minutes, until the mixture thickens slightly.

Remove the pan from the heat and whisk in the Nutella, making sure it dissolves completely. Place a fine mesh strainer over a bowl and pour the mixture over to catch any solid bits. Refrigerate the gelato base until thoroughly chilled, preferably overnight.

Once chilled, give the mixture a final stir and pour it into an ice cream maker. Churn for slightly less time than recommended for ice cream (mine recommends 20 minutes of churning for ice cream and I churned it for 15 minutes). Immediately transfer to a freezer-safe container and continue to freeze for at least one additional hour.

Before serving, remove from freezer to let soften slightly. Serve in generous scoops topped, perhaps, with salted chopped hazelnuts, chocolate sauce, cookies, or whatever else sounds delightful.