Preheat oven to 450°. Place a sheet pan in the oven while it preheats.
CHICKPEAS: Add the dried chickpeas to a separate sheet pan and dry roast them for 8 minutes, then remove from the oven and add the oil and spices. Toss to coat and roast another 8-10 minutes.
BRUSSELS SPROUTS: Add the halved brussels sprouts, half the olive oil, salt, garlic powder, paprika, and maple syrup to a bowl. Toss to coat. Remove the sheet pan from the oven and add the remaining olive oil to the pan, then the brussels sprouts face down. Place in the oven for 30 minutes, flipping halfway.
CASHEW WHIP: While the brussels roast, make the cashew whip. Add all ingredients to a high speed blender and blend until smooth.
ASSEMBLY: Spread the cashew whip onto a plate, top with the brussels, the grapes, and the chickpeas. Top with chopped parsley and pepper, if using.
