In a small bowl, stir together the paprika, salt, onion powder, garlic powder, black pepper, and cayenne pepper. I like making this first so it's ready to sprinkle into both the flour and the breadcrumb bowls later. Keeping it in one place also means the seasoning stays consistent throughout the batch, so no nugget tastes bland compared to another.
Melt the butter in a large skillet over medium heat, then stir in the panko breadcrumbs. Keep stirring for about five minutes until they turn a deep golden color, then remove them from the heat to cool. This one step genuinely transforms the texture, giving you crispy chicken nuggets that stay crunchy even after they've cooled down slightly.
Dice the chicken breast into bite-sized pieces and lay them on a cutting board. Cover with plastic wrap and gently pound each piece flat with a rolling pin or mallet. This tenderizes the chicken, speeds up cooking, and gives you that classic, familiar nugget shape everyone recognizes from childhood.
Line up three bowls: one with flour and a pinch of the spice mix, one with beaten eggs, and one with the cooled toasted breadcrumbs, parmesan, and the rest of the seasoning. Dip each chicken piece through flour, then egg, then breadcrumbs, pressing gently so the coating sticks all the way around with no bare spots.
Place the coated nuggets on an oiled wire rack set over a baking tray, then lightly mist the tops with oil spray. Bake at 390°F (200°C) for around 15 minutes, or until deep golden and cooked through. If you're after homemade chicken nuggets pan fried instead, you can finish them in a lightly oiled skillet for a couple of minutes per side rather than using the oven.
Once out of the oven, leave the nuggets on the wire rack for a few minutes before digging in. This lets built-up steam escape from underneath the coating, which keeps the crust crispy instead of turning soggy on the bottom.