Preheat the oven to 425°F (220°C) and line 2 baking sheets with parchment paper.

Combine the ground chicken, grated Parmesan cheese, garlic powder, onion powder, paprika, salt, and black pepper in a large mixing bowl.

Mix the chicken mixture gently until the seasonings and cheese are evenly distributed.

Whisk the egg in one large mixing bowl and place the panko breadcrumbs in the second large mixing bowl.

Shape the seasoned chicken into about 20 bite-size nugget pieces, using approximately 1 tablespoon of mixture for each nugget.

Dip each chicken nugget into the whisked egg, then coat it completely with panko breadcrumbs.

Arrange the breaded chicken nuggets in a single layer on one prepared baking sheet and spray them lightly with avocado oil spray.

Toss the broccoli florets with avocado oil in a large mixing bowl, then spread them on the second prepared baking sheet.

Bake the chicken nuggets and broccoli for 20 minutes, rotating the baking sheets halfway through cooking.

Continue baking the chicken nuggets for up to 5 minutes if needed, until browned and their internal temperature reaches 165°F (74°C).

Whisk the Dijon mustard and maple syrup together in a small bowl until the maple mustard sauce is smooth.

Serve the baked chicken nuggets hot with maple mustard sauce and roasted broccoli.