Preheat the oven to 300°F. Line a sheet pan with parchment paper.
Mix oil, syrup, vanilla, and salt in a large bowl. Stir in the oats and hazelnuts and toss to coat well.
Spread the oat and hazelnut mixture onto the sheet pan and pat down into an even layer.
Place in the middle of the preheated oven and bake for 20 - 30 minutes, stirring every 10 minutes to toast it evenly.
Remove it from the oven as soon as the nuts and oats just start to brown. Do NOT overcook this. The trick is to take it out of the oven before it gets crisp. It will crisp up as it cools.
Let it cool for about 5 minutes and then mix in the dates and the chocolate and stir it well to allow the chocolate to melt and coat everything lightly.
Once completely cool, place it in jars or a large bowl and place it in the fridge for an hour or two for the chocolate to firm up.