Warm a large skillet over medium heat. Brown the kielbasa rounds until lightly crisp, 4–6 minutes. Drain excess fat.
Whisk the cider, apple jelly, brown sugar, Dijon, vinegar, garlic, red pepper flakes, salt, and pepper in a bowl.
Pour the glaze into the skillet. Simmer, stirring often, until the sauce reduces slightly, 6–8 minutes.
Stir cornstarch with water. Drizzle into the pan and cook until the glaze turns glossy and clings, 1–2 minutes.
Stir in butter to finish. Sprinkle with parsley and serve warm with picks.
Notes
Swap apple jelly with apple butter for a deeper fruit note, or add a splash of bourbon to the glaze. Keep leftovers in an airtight container up to 3 days; rewarm gently over low heat with a spoonful of cider.This recipe is an original creation inspired by classic Apple Glazed Kielbasa Bites flavors. All ingredient ratios and instructions are independently developed.