Add first 6 ingredients to a roasting pan (approx. 18”x13”) and mix to combine.
Season the spareribs with the salt evenly and on both sides. Place ribs over apple/onion mixture, cover tightly with aluminum foil and place in the preheated oven for 2 hours.
While ribs are braising, make the glaze. First, warm the cider and sugar in a small sauce pan until the sugar is dissolved. When the sugar is dissolved, add the honey and mustard and mix to incorporate. Set this aside to cool and slightly thicken.
After 2 hours, carefully remove the pan from the oven and uncover. Place the brats in the pan and arrange them around the ribs.
Apply the glaze to the ribs and brats using a brush or spoon and place back in the oven (uncovered). After about 30 minutes, reapply the glaze. Do this until the glaze is dark golden-brown and the internal temperature of the brats is at least 150°.
When the glaze is golden-brown and the brats are done, allow the ribs to cool enough to handle and slice into individual ribs for easy eating. You can serve the remainder of the glaze on the side, or assemble the ribs and brats on a platter and pour the rest of the glaze on top.
Serve with mustard, pretzels, sauerkraut and a large stein of Lager.
As an optional side sauce, drain the apples/onion mixture and purée in a blender until smooth. Season to taste with salt, brown sugar and a pinch of allspice. You can serve this rustic savory apple sauce as an additional side sauce for dipping.