Preheat oven to 375°F. Line a baking sheet with aluminum foil and spray with non-stick cooking spray.
In a bowl beat egg white until soft peaks form. Fold in walnuts. Add sea salt, ancho chile and 2 tablespoons maple syrup. Stir to combine.
Pour walnuts on baking sheet and bake for 25 minutes, stirring nuts after 12 minutes.
Allow walnuts to cool slightly before drizzling remaining maple syrup on top. Stir once more to combine.
Allow walnuts to cool completely before serving.