Preheat your oven to 400°F. Take a baking sheet and spray it with nonstick spray to prevent the chicken from sticking.
In a shallow bowl, whisk the egg until it’s well blended, creating a smooth mixture that's perfect for coating.
In another shallow bowl, stir together the Panko breadcrumbs, Parmesan cheese, salt, pepper, and garlic powder. This mixture will give the chicken its delicious crispy crust.
Take each boneless, skinless chicken breast and dip it into the egg mixture, ensuring both sides are well coated. Don’t forget to shake off any excess!
Next, dip the chicken into the breadcrumb mixture, pressing down to make sure it's coated thoroughly on both sides. Place the coated chicken onto the prepared baking sheet.
Repeat this process for all four chicken breasts, arranging them in a single layer on the baking sheet.
Once all the chicken is on the baking sheet, lightly spray the top of each breast with olive oil spray or baking spray to enhance browning.
Put the baking sheet in your preheated oven and bake for about 15 minutes, or until the chicken is crispy and golden.
After 15 minutes, take the baking sheet out of the oven. Add the frozen broccoli around the chicken, ensuring that the pieces are broken apart and laid as flat as possible.
Return the baking sheet to the oven and continue baking for another 5 minutes. The broccoli will become tender and vibrant.
Next, remove the baking sheet once again and spread marinara sauce evenly over each chicken breast. Top each with the freshly shredded mozzarella cheese.
Place the baking sheet back in the oven for about 3 to 4 minutes, or until the cheese is melted and bubbly. If you want to get a nice golden top, you can switch the oven to broil for an additional 2 minutes. Just keep a close eye on it, so nothing burns!
Lastly, remove the baking sheet from the oven. Top the baked chicken and broccoli with the chopped basil for a fresh finish. Serve hot and enjoy!
