Preheat oven to 350°. In a bowl, combine sugar, corn syrup, 1/4 tsp. each salt and cardamom, the cayenne, and cloves. Stir in nuts. Spread onto a rimmed baking sheet lined with parchment paper.
Bake, stirring once in a while with a fork, until syrup is deep golden, about 15 minutes. Stir again, then transfer nuts on paper to a work surface. Let nuts cool, breaking them up after 5 minutes.
Whisk oil, vinegar, pepper, shallot, and remaining 1/4 tsp. each salt and cardamom in a large bowl. Gently toss with spinach, pears, and nuts. Serve immediately.
Note: Nutritional analysis is per 1 1/2-cup serving.