Preheat oven to 350 degrees F and grill to medium-high.
In a large saucepan, saute the onion, garlic, and horseradish over medium-high heat. Add the vodka and scrape the bottom of the pan with your wooden spoon or rubber spatula to deglaze the yummy bits off the bottom. Add the pineapple and tomatoes and bring to a simmer. Let it simmer for 10 minutes. Add the molasses, vinegar, honey, sugar, mustard powder, oregano, bay leaves, Worcestershire sauce, and ketchup. Allow it to simmer for 2 hours.
Season the ribs with salt and freshly ground black pepper and rub with a little olive oil. Grill the ribs for about 5 minutes per side. In a braising pan, place the ribs and 1/2 of the sauce over the ribs and cover the pan with a lid. Save the other 1/2 of the sauce for the final plating. Add 1 cup of water to the ribs and let it simmer for 3 1/2 to 4 hours, until the meat is tender but is still on the bone. Remove the ribs from the liquid.
Serving Suggestions: Place 2 ribs on each plate. Generously ladle the hot BBQ sauce over the ribs and top with grilled pineapple and sliced limes.