Preheat the oven to 400°F. Line a 15x10-inch baking pan with foil; coat foil with cooking spray. Place the potatoes in one half of prepared pan. Drizzle with 1 Tbsp. oil and sprinkle with salt and pepper. Bake 20 minutes, stirring once.
Meanwhile, in a large bowl combine next four ingredients (through garlic powder). Add the ground beef; mix lightly until combined. Shape into four 3 ½x2-inch meat loaves.
In a medium bowl drizzle the green beans with 1 tsp. oil and sprinkle with salt and pepper; toss to coat. Place loaves and green beans in pan with potatoes. Bake for 20 to 23 minutes more or until loaves are done (160°F) and potatoes and beans are tender.
Spoon ¼ cup barbecue sauce over meat loaves; cover and let stand 10 minutes. Serve with potatoes and beans.