I need oven cooking instructions for Pork back ribs
1/2 cup ancho chile powder 1/4 cup white sugar 1/4 cup brown sugar 1/4 cup salt 2 tablespoons freshly ground black pepper 1 tablespoon ground cumin 1 teaspoon dry mustard 1 teaspoon ground cayenne pepper 1/2 teaspoon ground dried chipotle pepper 1 rack baby back pork ribs 1 cup barbeque sauce Directions Preheat oven to 250 degrees F (120 degrees C)Mix ancho chile powder, white sugar, brown sugar, salt, black pepper, cumin, dry mustard, cayenne pepper, and chipotle pepper in a small bowl until combinedPlace ribs meat-side down on aluminum foilPrick back of rib rack several times with a knifeGenerously apply coating of dry rub to all sides of rib rackWith rib rack meat-side down, fold foil around it to create a tight sealTransfer to sheet panBake in preheated oven until tender and cooked through, about 2 hoursRemove and cool 15 minutesIncrease oven temperature to 350 degrees F (175 degrees C)Open foil, drain and discard any accumulated juices and fatBrush barbeque sauce on all sides of rackPlace rack meat-side up and return to oven, leaving foil openBake for 10 minutes, remove from oven, and brush another layer of barbeque sauce on meat-side onlyRepeat baking and brushing with sauce 4 more times, for a total of 50 minutes baking timeCut rack into individual rib segments and serve with more barbeque sauce'