In a stand mixer fitted with the paddle or whisk attachment (or using a hand mixer), add softened butter and sea salt.
Whip for 3–4 minutes, until light, pale, and very fluffy.
Add the prepared cranberry sauce, maple syrup, and orange zest.
Beat again for 30–60 seconds, just until fully blended and creamy. (If you prefer a streaked, marbled look, mix less. For a fully pink whipped butter, mix more).
Add more maple syrup for sweetness.
Add more zest for brightness.
Add a pinch of salt if your cranberry sauce is very sweet.
Transfer to jars or ramekins.
Refrigerate for at least 30 minutes to slightly firm up.
Keeps 7–10 days in the fridge.