Warm a small pan over medium heat. Add the butter and sugar and stir until the butter is melted. Add the walnuts and toss until they begin to brown, about 5 minutes.
Stir in the rosemary and cayenne and continue to toss just a few seconds to release the aroma. Remove from the heat and season with salt and pepper, to taste.
Once the nuts are done you can add to the salad on top if serving right away.
Add the edamame, dried cranberries and sliced apples to the bowl of kale. Toss everything together. Top with warm nuts and serve.