Preheat your oven to 350°F (175°C).

Spread the hazelnuts on a baking sheet in a single layer.

Roast in the oven for about 10-12 minutes or until the skins darken and become cracked.

Once roasted, let the hazelnuts cool slightly.

Place them on a kitchen towel and rub them together to remove the skins. It's okay if not all the skins come off.

Place the roasted hazelnuts in a food processor and blend until they form a smooth hazelnut butter. This may take 10-15 minutes, and you might need to scrape down the sides occasionally.

Add the powdered sugar, cocoa powder, vanilla extract, and salt to the hazelnut butter in the food processor.

Blend again until all the ingredients are well combined and smooth.

With the food processor running, slowly add the vegetable oil, followed by the milk. Continue blending until the mixture is silky and well incorporated.

If your Nutella is too thick, you can add a bit more milk until you reach your desired consistency.

Taste the homemade Nutella and adjust the sweetness or cocoa level according to your preference by adding more sugar or cocoa if needed.

Transfer the homemade Nutella to a clean, airtight container and store it in the refrigerator. It will thicken as it cools.