Wash the kale, lettuce or salad greens, and Brussels sprouts thoroughly to remove any dirt and grime. Trim the ends of the Brussels sprouts and remove any bad leaves.
Carefully slice the Brussels sprouts, and do the same with the kale, making sure to remove any tough stems. Massage the kale with a tiny bit of olive oil and lemon can make it softer and less bitter. Slice the lettuce or salad greens into small, bite sized pieces.
In a small bowl, whisk together the olive oil, Dijon mustard, maple syrup, apple cider vinegar, garlic powder, onion powder, dried thyme, salt, and pepper. Adjust the ingredients to taste—if you want it sweeter, add more maple syrup; for a tangier dressing, add a bit more vinegar.
In a large bowl, combine the Brussels sprouts, kale, lettuce or salad greens, diced avocado, almonds or pecans, cranberries (optional), and grated Parmesan cheese. Just before serving, drizzle the vinaigrette dressing over the top of the salad and toss everything together until evenly coated.