Preheat oven to 300 degrees F (148 degrees C).
Combine together Garlic Powder (2 teaspoon), Onion Powder (2 teaspoon), Paprika (2 teaspoon), Chili Powder (2 teaspoon), Ground Black Pepper (1/2 teaspoon), Salt (4 teaspoon) and Dried Oregano (1 1/2 teaspoon).
Peel off the tough membrane that covers the bony side of the Pork Baby Back Ribs (4 pound), remove excess fat, then rinse really well. Place on a baking sheet or tray lined with foil.
Squeeze a Lemon (2) over each rack of ribs. Rub the seasoning all over the ribs on both sides. Cover tray with foil and bake for 2 1/2 hours.
Remove ribs from the oven, remove foil and spread the tops of the ribs with the Barbecue Sauce (1 cup). Increase oven temperature to 460 degrees F (237 degrees C). Return ribs to the oven, uncovered, and bake for 10 more minutes.
Put on broil for 2 minutes or until the sauce is caramelized.
Remove ribs from oven again, flip them over gently, and spread Barbecue Sauce (1 cup) on the bony part of the ribs. Then broil for another 3 minutes.
Allow ribs to rest for 10 minutes then serve.