Preheat the oven to 400°F
Line a baking sheet with foil or parchment paper
Place the kielbasa on the baking sheet
Slice the kielbasa into pieces or leave it whole
Bake for 15 to 20 minutes if sliced
Bake for 25 to 30 minutes if whole
Turn the kielbasa halfway through cooking
Check that the kielbasa is heated through and browned
Remove from the oven
Let it rest for a few minutes before serving