Preheat the oven to 300°F and line a large baking sheet with parchment paper.
Combine the honey and the butter in a small saucepan. Over medium-low heat, heat the honey butter mixture until all of the butter has completely melted, stirring regularly. Continue to cook the mixture until it begins to bubble. Once bubbling, cook for 1 minute, then remove from the heat immediately.
Add the cashews to a large mixing bowl and pour the prepared honey butter mixture over them, stirring to coat the nuts completely. Pour the cashew nuts onto the parchment-lined baking sheet and spread them out in a single layer. Bake for 25 minutes, stirring every 10 minutes during the baking time. Let the cashews cool for 10 minutes on the baking sheet before adding the cinnamon sugar.
While the cashews are cooling, make the cinnamon sugar. In a small bowl, add the granulated sugar, brown sugar, kosher salt and cinnamon, stirring to combine.
After the nuts have cooled for 10 minutes, transfer them to a large mixing bowl. Sprinkle all of the cinnamon sugar mixture on top and toss them with a wooden spoon to coat the cashews entirely with the sugar. This will take several minutes of tossing to get the nuts completely coated.
Let the cashews cool completely before serving or storing.
Notes
It is very important to let the cashews cool for only 10 minutes after baking. If they cool any longer, they will become hard, and the sugar will not stick to them, and if the sugar is added when they are too hot, the sugar will melt.
The cashews are baked at a low temperature to prevent the nuts and honey from burning.
Store honey roasted cashews in an airtight container for up to 2 weeks at room temperature.