Rinse both racks with cold water and place them on a layer of paper towels on a half sheet pan, place another layer of paper towels on top. Press down on the paper towels on the top to make sure they are as dry as possible. If you have the time, and space, I recommend placing them on a fresh layer of paper towels on the half sheet pan, and refrigerating them, uncovered, overnight to allow them to dry out thoroughly.
To remove the membrane from the underside of the ribs, start by laying one rack bone side up on a large cutting board. Look for a thin, silvery white layer of tissue covering the back of the ribs, this is the membrane. Using the tip of a small paring knife, slide it under the membrane at one end, near a bone. Gently pry it up to create a small separation.
If you have a good grip, you can simply pinch the loosened membrane and pull it towards the opposite end of the rack, slowly peeling it away from the ribs. Or, if the membrane feels slippery, grab a paper towel and hold it over the loosened area. Now, firmly pinch the membrane through the paper towel and pull steadily in the direction away from the loosened end. The paper towel will give you extra traction to remove the membrane more easily.
Once you've removed a good portion of the membrane, keep pulling steadily and slowly towards the other end of the rack. It should hopefully come off in one large piece. If you encounter any areas where the membrane tears or becomes difficult to remove, use the knife tip to carefully scrape it free from the ribs. Be gentle to avoid gouging the meat.
After you have successfully removed the membrane from one rack, repeat steps 2-4 to remove the membrane from the other rack.
Once the membrane is removed, spread one tablespoon of yellow mustard on each side of both racks of ribs. Then, spread 2-3 tablespoons of the dry rub on each side of both racks of ribs.
Lay a large sheet of extra wide heavy duty aluminum foil on a flat surface. Then, lay a piece of parchment, large enough to wrap the rack of ribs in, on top of the foil.
Place one prepared rack of ribs in the center of the parchment. Then, wrap the parchment around the rack of ribs. Next, wrap the foil around the parchment wrapped ribs, making sure to seal the foil tightly.
Repeat steps 6-8 with the other rack of ribs. Place both racks on a half-sheet pan lined with extra wide heavy-duty aluminum foil, and place in the refrigerator for at least 2 hours, or up to 24 hours if you have the time.
After the ribs have been in the refrigerator for your preferred amount of time, remove them. Then, preheat your oven to 300°F. Once the oven reaches temperature, place the pan with the ribs in the oven for 2 hours.
When you have about 10 minutes left on the cooking time, prepare the wet rub. Start by melting the unsalted butter in a medium size bowl. Next, add the dark brown sugar and honey. Then, use a whisk to combine them until smooth and fully emulsified.
Remove the ribs from the oven and increase the temperature to 325°F.
Place one wrapped rack on a flat surface and unwrap it. Take care when you unwrap, as it will be hot, and there will be a fair amount of liquid inside the foil. Then, place half of the wet rub on top of the rack of ribs.
Allow the wet rub to melt slightly, then spread it over the entire top of the rack of ribs. Then, re-wrap the ribs with the parchment and foil and place them back on the sheet pan.
Repeat steps 13-14 with the other rack. Return to the 325°F oven and bake for 1 hour.
Line another half-sheet pan with the extra wide heavy-duty aluminum foil, then place a half-sheet wire rack inside the pan. Remove the ribs from the oven and set the oven to broil.
Carefully unwrap the ribs and using two pairs of tongs, one in each hand, place both racks on top of the prepared pan, rib side up. At this point, the ribs will likely be falling off the bone, so try not to break the racks when transferring.
Next, add your favorite barbecue sauce to each rack. Then, use a basting brush to spread the sauce over the entire surface of the ribs. Place the pan in the oven and broil for 5 minutes.
Remove the ribs from the oven and, using the tongs, carefully turn them over. Then, add sauce to the tops of both racks and use the basting brush to spread the sauce over both racks. Return to the oven and broil for 5 minutes.
Remove from the oven and allow to cool for 10-15 minutes before cutting and serving
Yield 6-8 servings