Preheat your oven to a robust 400°F (200°C). Line a large, sturdy baking sheet with aluminum foil for easier cleanup, then place an oven-safe wire rack on top. Using a wire rack is crucial here – it allows air to circulate all around the chicken, ensuring truly crispy skin on every surface, not just the top.

In a small bowl, combine the smoked paprika, granulated garlic, onion powder, dried oregano, cayenne pepper (if using), coarse sea salt, and freshly ground black pepper. Stir them together until well blended. This simple, yet powerful blend provides a deep, savory flavor with a hint of smokiness.

Begin by thoroughly patting the chicken leg quarters dry with paper towels. This step is non-negotiable for crispy skin! Excess moisture creates steam, which prevents the skin from crisping. Next, gently lift the skin over the thigh portion of each quarter, being careful not to detach it completely. This creates a pocket. Sprinkle about 1/2 to 1 teaspoon of your spice blend directly onto the meat under the skin, using your fingertips to rub it in. Seasoning directly on the meat ensures flavor penetrates deeply, beyond just the skin. Now, lightly brush both sides of each chicken quarter with olive oil (or melted butter). The fat helps to distribute the spices and encourages beautiful browning and crisping.

Evenly sprinkle the remaining spice mixture over the entire surface of each chicken quarter, ensuring good coverage. Place the seasoned chicken leg quarters, skin-side up, on the prepared wire rack. Make sure there's ample space between each piece for optimal air circulation during baking.

Transfer the baking sheet to the center rack of your preheated 400°F (200°C) oven. Bake for 30 minutes. This initial high heat blast is key to rendering the fat under the skin and kickstarting the browning process, leading to that irresistible crispy texture.

After 30 minutes, carefully remove the baking sheet from the oven. Using sturdy tongs, flip each chicken quarter over so it's now skin-side down. Return to the oven and continue baking for another 15-25 minutes, or until an instant-read thermometer inserted into the thickest part of the thigh (avoiding the bone) registers between 175°F and 185°F (80-85°C). While 165°F is safe, dark meat like leg quarters benefits greatly from cooking to a slightly higher temperature, as it allows collagen to break down more effectively, resulting in incredibly tender, juicy meat that practically falls off the bone.

For extra-crispy, golden-brown skin, turn your oven's broiler to high. Keep a close eye on the chicken! Broil the chicken, skin-side up, for 3-5 minutes, watching constantly to prevent burning. If desired, you can briefly flip and broil the other side for a minute or two, but the main goal is to crisp the top skin. This step gives you that perfect, crackling skin finish.

Once the chicken has reached its ideal temperature and desired crispness, transfer the leg quarters to a clean cutting board or serving platter. Tent them loosely with aluminum foil and let them rest for 5-10 minutes. This crucial resting period allows the juices to redistribute throughout the meat, ensuring every bite is as tender and succulent as possible. Skipping this step often leads to dry chicken!

Garnish with fresh chopped parsley or cilantro, if using. Serve your perfectly baked chicken hindquarters hot alongside your favorite side dishes, like roasted vegetables, mashed potatoes, or a fresh salad. Enjoy your perfectly juicy, crispy, and flavorful chicken!