In a mixing bowl, combine walnuts and pumpkin seeds. In a separate bowl, mix maple syrup, olive oil, salt, and pepper. Pour over nuts and toss well. Spread on a parchment-lined baking sheet and bake on the lowest oven rack for about 35 minutes, rotating halfway. Once cooled, break into bite-sized pieces.
While the brittle cools, whisk together dressing ingredients and prepare salad ingredients.
Toss together all salad ingredients. Add dressing just before serving and toss well to coat. Top with brittle.
Notes
*We recommend using a sweet, tart apple like honeycrisp or granny smith.*