It doesn't get much more classic than these maple-sweetened walnuts.
Preheat oven to 350 degrees. Spread walnuts in a single layer on a rimmed baking sheet; toast in oven, stirring occasionally, until fragrant, about 10 minutes. Let cool completely.
Meanwhile, combine maple sugar, salt, and cinnamon in a medium bowl; set aside. In a large, deep skillet, combine brandy, vanilla, maple syrup, and butter. Bring to a boil over medium heat, and cook until liquid is reduced by half, about 5 minutes. Stir in nuts, and continue cooking, stirring, until skillet is almost dry, about 3 minutes more.
Remove from heat, and immediately add reserved sugar mixture to hot nut mixture; toss until well coated. Spread out coated nuts on a baking sheet lined with parchment paper, and let cool completely, 6 hours or overnight.
Nuts can be stored in airtight containers at room temperature up to 2 weeks.