In a medium saucepan, combine the balsamic vinegar, ketchup, brown sugar, pressed garlic, worcestershire sauce, prepared mustard paste, smoked paprika, salt, and pepper. Stir everything together until well combined and smooth. This glaze base will be the foundation of your sauce, so make sure all ingredients are fully incorporated before cooking.

Bring the glaze mixture to a simmer over medium heat and cook for 15 to 20 minutes, stirring occasionally, until the sauce reduces by about one-third and thickens slightly. This reduction concentrates the flavors and creates a richer, more complex sauce. I like to use this time to prepare the ribs for cooking.

While the glaze simmers, place the cut spareribs in a large pot and cover them completely with the apple cider. Bring to a boil over high heat, then immediately reduce the heat to low and maintain a gentle simmer for 1 to 2 hours, until the ribs are tender but still hold their shape. The poaching process tenderizes the meat and infuses it with subtle apple flavor, which will complement the savory-sweet glaze beautifully.

When the glaze has reduced sufficiently, remove it from heat and stir in the horseradish and liquid smoke, along with 3 tablespoons of the reserved apple cider (or water). Stir until fully combined. I find that adding the horseradish at the end preserves its sharp, peppery bite rather than mellowing it out during cooking.

Drain the poached ribs thoroughly and arrange them in a single layer on a baking sheet or large baking dish. Generously brush the ribs with the finished glaze from Step 4, making sure each rib is well coated on both sides. Reserve the remaining glaze for basting during baking.

Preheat your oven to 350°F and bake the glazed ribs for 25 to 35 minutes. Brush the ribs with the reserved glaze every 8 to 10 minutes during baking so they develop a rich, caramelized coating. The ribs are done when the glaze is thick and sticky and begins to brown lightly at the edges.