Preheat the oven to 375 degrees F, and place the hazelnuts in a single layer on a baking sheet. When the oven is preheated, roast them until they are very aromatic and the skins are cracking, about 5 minutes. Let them cool for at least 5 minutes, and then they can be rubbed together in your hands, or in a dish towel, and the skins should flake away. (Some tiny bits of skin will remain, and that's okay.) Roughly chop the nuts and set them aside.
Turn the oven down to 350 degrees F, and a baking sheet with parchment paper.
In a medium-sized mixing bowl combine the oats, hazelnut meal, and salt. Mix and set aside.
In a large mixing bowl, combine the softened butter, sugar, orange zest and juice, honey, and vanilla. Mix until smooth.
Add the dry ingredients and roasted, chopped hazelnuts to the butter mixture and mix until everything is evenly blended.
Pour the granola mixture onto the parchment-lined baking sheets. Use a flat-bottomed metal spatula to flatten out the top surface. It should be about ½-inch thick and cover the sheet.
Place the baking sheet in the preheated 350 degree F oven, and roast until it's a dark golden brown, about 30 minutes.
Let it cool on the baking sheet until it's very hard, about 30 minutes.
Break and/or crumble the granola into the size pieces you like. (I like a mix of big and small chunks.)
Serve with a sprinkling of mini chocolate chips on top if desired. (As you can see, I desired them.)