Tequila BBQ Spare Ribs

Name: Tequila BBQ Spare Ribs
Ingredients: Two 4-pound slabs pork spare ribs, St. Louis style-cut; 2 tablespoons ground cumin; 2 tablespoons granulated garlic; 2 tablespoons onion powder; 2 tablespoons paprika; 2 tablespoons kosher salt; 2 teaspoons ground black pepper; 1 teaspoon ancho chile powder; Tequila BBQ sauce, for serving, recipe follows; 1 small California/New Mexico dried chile; One 6-ounce can tomato paste; 1 cup packed light brown sugar; 1/2 cup white tequila; 1/4 cup lime juice; 1 tablespoon minced fresh garlic; 1 tablespoon molasses; Kosher salt and freshly ground black pepper