In a small bowl, stir together onion puree, 2 Tbsp mayo, 1 tsp black pepper, 1 Tbsp salt and hot sauce if using.
Place chicken drumsticks into a large mixing bowl or soup pot then pour on the marinade and toss to coat the drumsticks.
Cover with lid or plastic wrap and refrigerate at least 6 to 8 hours or (preferably) overnight.
Line a rimmed baking sheet with parchment paper or foil and bake skin-side-up at 400˚F for 45 minutes in the oven then turn drumsticks over (skin-side-down) and bake another 15 minutes.
For extra crispy skin, turn drumsticks again and broil 3 minutes or until skin is browned and crisp. Enjoy!