Position an oven rack in the center of the oven and preheat to 325 degrees F. Line a baking sheet with parchment paper.
Whisk the egg white in a bowl until foamy. Add the BBQ rub and syrup and mix until combined. Add the almonds and cashews to the bowl and mix.
Spread the nut mixture on the prepared baking sheet. Sprinkle with a little sugar and cook on the middle rack until golden brown, stirring halfway, 20 to 25 minutes. Let cool for 15 to 30 minutes. Store in an airtight container for up to a week.