Preheat the oven to 325°F (160°C) and line a baking sheet with parchment paper.

In a mixing bowl, combine the macadamia nuts, honey, melted butter, sea salt, and cinnamon (if using). Toss well to coat evenly.

Spread the coated nuts in a single layer on the prepared baking sheet.

Roast in the preheated oven for 12-15 minutes, stirring halfway through to ensure even roasting.

Remove from the oven and let cool completely. The nuts will crisp up as they cool.

Once cooled, transfer to an airtight container or serve immediately.