Prepare ribs: Place a rack of ribs meat side down on a baking sheet; remove the thin, papery membrane from the back of the rack by inserting a slender implement, such as a butter knife or the tip of a meat thermometer, under it; the best place to start is on one of the middle bones.
Using a dish cloth, paper towel, or pliers to gain a secure grip, peel off the membrane; repeat with remaining racks.
Generously season both sides of ribs with salt, cracked black pepper, and hot pepper flakes.
Cover the ribs with plastic wrap and refrigerate them while you set up the smoker.
Set up and light the smoker according to the manufacturer’s instructions and preheat to low; add wood chips per manufacturer’s instructions.
When ready to cook, brush and oil the smoker rack; place ribs bone side down on the rack and smoke until cooked through, 4-5 hours.
Prepare sauce: To a saucepan add all the sauce ingredients; whisk to blend.
Gradually bring sauce to a boil over medium heat, whisking as needed.
Decrease heat slightly and let the sauce simmer gently until thick and richly flavored, about 10 minutes; serve warm or at room temperatue.
When ribs are done, transfer to a large platter or cutting board; let rest for a few minutes.
Cut racks in half or into 1-2 rib pieces; serve immediately with sauce.