Preheat oven to 350 degrees
Measure out the garlic powder, kosher salt, black pepper, red pepper, beau monde and celery salt. Whisk to combine and set aside.
Remove your chicken from the packaging and place bone side up onto a parchment lined sheet. Season liberally with the spice mixture then roll each side in to form them as they were in the package originally.
Place chicken in the center of a lightly oiled sheet pan.
Slice the zucchini and yellow squash and place on one side of the chicken.
Toss potatoes or hashbrowns lightly in olive oil then place them on the opposite side of the pan.
Season liberally with spice mixture, drizzle olive oil over the entire pan and place in the oven.
Cook until the internal temperature of the chicken reaches 165 degrees stirring vegetables and potatoes during cooking.
*Optional - Once the chicken has reached temperature, brush with barbecue sauce and return to oven for 5 minutes.
Remove from oven, add fresh parsley and serve.