Adjust oven rack to lowest position and heat oven to 250 degrees F. Mix brown sugar, paprika, salt, pepper and garlic powder in small bowl
. Pat roast dry and place on rack set over foil-lined shallow baking sheet
. Lightly sprinkle top and sides of roast with salt, brush with half the mustard and sprinkle with half the spice rub. Carefully turn roast over. Sprinkle with a little salt, brush with remaining mustard and sprinkle with remaining spice rub. Roast until meat
thermometer registers 170 degrees F, 9 to 11 hours, depending on size. Transfer pork
to platter and cool enough to handle, about 1 hour. Cut roast into 1- to 2-inch chunks and shred meat into a large bowl. Add enough pan drippings to moisten pork and stir to combine.