In large frying pan, place walnut halves and then place over medium-high heat. Cook, stirring constantly to prevent burning, until walnuts are lightly toasted, about 2 to 3 minutes. Add maple syrup to pan and continue to cook, stirring constantly, until maple syrup has coated walnuts and no syrup, or very little, is left in pan, about another minute. Remove frying pan from heat, sprinkle smoked paprika over candied walnuts, and stir to evenly incorporate. Transfer walnuts to parchment-lined baking tray and spread out as best you can in single layer. Set aside to cool while making soup.