Heat a pan on high and place the hazelnuts in the pan.
Move the pan constantly for 8 to 10 minutes, or the skin begins to come off and they start to brown.
Remove from the heat and transfer the hazelnuts to a clean kitchen towel.
Gently rub them with the towel until the skin comes off. You might need a bit of help with a knife to get most or all of the skin off of the hazelnuts.
Place hazelnuts in a heavy-duty blender or food processor and blend until it forms hazelnut butter. Scrape the sides as needed.
Add the powdered sugar, cocoa powder, vanilla, and coconut oil and mix until combined.
Place the semisweet chocolate and the milk chocolate in a microwave-safe bowl.
Microwave in 20 second intervals, stirring in between, until completely melted. Make sure you don't burn the chocolate.
Pour the chocolate into your hazelnut mixture and continue mixing until it is evenly combined.
At this point, you can strain the Nutella through a fine-mesh strainer and then through cheesecloth to make it smoother.
Pour into a clean jar, and let it cool completely.