Remove skin from ribs. Season both sides of rack liberally with salt, pepper, garlic powder and paprika; set aside.
Slice onions into 1/2 inch rings and place them on the bottom of a large roasting pan (or two smaller ones) Ribs should cook in a single layer. The onion slices create a layer that will keep the ribs elevated so that they aren't sitting in liquid.
Pour just enough beer into the pan to cover the bottom of the pan. Arrange racks in a single layer on top of onion slices. Cover pan with two layers of aluminum foil. If your pan has a lid, use one layer of foil and the lid.
Bake at 300 degrees for 4 hours. Remove ribs from oven and uncover. Carefully drain pan juices, baste ribs with Barbeque sauce and return to oven. Continue baking, un-covered for 15 minutes. Remove ribs from oven, tent with foil and let rest for 15 minutes before serving.