In a medium saucepan over medium heat, mix cream, milk, and ½ cup of sugar whisking until granules are dissolved, about 5 minutes. Remove from heat.
Meanwhile, in a stand mixer fitted with the whisk attachment, add ¼ cup of sugar to the egg yolks. Using a hand held mixer, beat the sugar & yolks until the mixture is thick and pale yellow, about 5 minutes.
Stream about a half cup of the warm cream mixture into the eggs, whisking the whole time. Pour the entire mixture back into the saucepan.
Continuing to whisk often, cook it on medium-low heat for about 8 to 10 minutes, or until it's thickened. (You should be able to coat the back of a wooden spoon, draw a line down the middle with your finger and have the line stay visible. Careful not to make scrambled egg custard!) Remove from heat.
Add Nutella and vanilla extract to the warm mixture, whisking together until it's uniform and well-mixed.
Refrigerate the mixture for a few to hours to cool it down. (If you're in a rush, you can speed up the process by placing the bowl with the custard over another bowl filled with ice and a little water -- an ice bath -- and whisking it in there for a while, but honestly, it's kind of a pain.
When the mixture is cooled, pour it into the canister of an ice cream maker and follow the manufacturer's instructions churning to a soft serve consistency.
Transfer the soft serve ice cream it into a freezer-safe container and freeze for 4 to 6 hours to achieve a scoopable consistency.