01 - Preheat oven to 350°F. Line a baking sheet with parchment paper.
02 - In a mixing bowl, combine the maple syrup, ground cinnamon, fine sea salt, and vanilla extract. Whisk until smooth and well blended.
03 - Add the walnut halves to the bowl and toss thoroughly until every piece is evenly coated with the maple cinnamon mixture.
04 - Spread the coated walnuts in a single layer on the prepared baking sheet, ensuring they are not crowded together.
05 - Bake for 12 to 15 minutes, stirring once halfway through, until the walnuts develop a glossy sheen and release a warm, toasty aroma.
06 - Remove from the oven and let the walnuts cool completely on the baking sheet. The maple glaze will harden and set as they cool.
07 - Transfer the cooled walnuts to an airtight container and store at room temperature for up to 1 week.