Heat oven to 400°F (200°C) and line a large rimmed baking sheet with foil or parchment paper.
Spread the halved baby potatoes over one-third of the pan. Toss with olive oil, garlic powder, salt, and pepper until evenly coated.
Place chicken thighs to the other end of the pan, skin side up. Sprinkle with salt, pepper, and paprika, then coat both sides generously with BBQ sauce.
Arrange the green beans and corn in the remaining space on the pan. Drizzle with olive oil and season with a little salt.
Roast for 30 to 35 minutes until the chicken hits 165°F internally, the skin is deep golden and crispy, the potatoes are tender when pierced with a fork, and the corn is lightly caramelized.
For a stickier, charred finish, switch to broil for the final 2 to 3 minutes, keeping a close eye on the chicken.
Finish with a scattering of fresh chopped parsley if desired and serve immediately.