Preheat the oven to 325°F. Line a baking sheet with parchment paper and set aside. Combine the nuts in a mixing bowl and set aside. Combine the butter and maple syrup in a small saucepan and place over medium heat, whisking together as the butter melts. In a small bowl, combine the brown sugar, chopped fresh rosemary, and the smoked sea salt.
Once the butter mixture begins to bubble, remove from the heat and pour over the nuts. Stir the nuts so they are well coated with the butter mixture. Sprinkle the brown sugar mixture over the nuts and stir to combine. Spread the nuts out on the prepared baking sheet.
Bake the nuts while stirring occasionally. Every 5 minutes, take the nuts out and stir them on the sheet pan. Continue roasting for a total of 17 to 20 minutes or until the nuts are well browned. When done, you can sprinkle with a little more of the smoked salt if you prefer.
Let the nuts cool completely, breaking up any large chunks as they cool. The nuts will harden as they cool. Enjoy!
Notes
*I used a blend of walnuts, pecans, cashews, almonds, and hazelnuts**You can substitute with an equal amount of honey.