Into a small bowl, add all the ingredients and whisk together till completely combined and smooth.
For the salad
Make the breadcrumb topping: Add 2 tbsp olive oil to a frying pan over medium-low heat. Add breadcrumbs, garlic powder, onion powder, salt and pepper and stir evenly to coat. Toast, stirring often, until breadcrumbs is golden brown - about 3-4 minutes. Set aside.
Thinly slice the brussels sprouts (use a mandolin if you prefer) and add to a large bowl or serving dish. Use your hands to break up the pieces.
Add in arugula, capers, hazelnuts and parmesan cheese. Drizzle with dressing and toss. Top with crispy panko bread crumbs and serve.
Video
Notes
Want to prepare this ahead of time? Brussels sprouts can be chopped and stored in the fridge along with prepared dressing (separate dressing). Breadcrumb topping can be made and stored on the counter. When ready to serve, assemble the salad as described in the instructions.This would also make a delicious dinner when topped with your favourite protein.