Preheat the oven to 350°F or 180°C.Add 3 cups hazelnuts to a rimmed baking sheet and roast them for 8 minutes.
Let them cool downfor 5 minutes, then add them to a high-speed blender with ¼ cup sugar and a ½ teaspoon olive oil.Tip: if your hazelnuts are unpeeled, remove some of the thin brown skin by rubbing them between your hands or in a kitchen towel.
Blend until they turn into a creamy hazelnut butter.Note: You’ll just need a few minutes if you use a high-speed blender like Vitamix. You might need up to 10 minutes with a food processor and scrape down the sides of the food processor occasionally.
Now add 3 tablespoons cacao powder, 1½ tablespoons vanilla extract, and 1 pinch salt.Blend for a few more minutes until combined.
Ultimately, you’ll want a smooth hazelnut spread that you can store in a jar in the refrigerator for a couple of months.The vegan Nutella will thicken a little as it cools in the fridge.