In a food processor or mini food processor, pulse butter until light and fluffy.
Whisk orange juice, powdered sugar, orange zest, and salt in a small bowl until the sugar is dissolved.
Add the orange juice mixture, a small amount at a time, pulsing until each addition is absorbed.
Continue adding the juice until all of it has been added, maintaining the emulsion.
Divide into portions, as desired, and freeze. Thaw completely (overnight) at room temperature.
Serve soft.
Notes
This recipe is based on a memory of whipped orange butter that I tasted years ago at a restaurant called " Ye Olde College Inn" in Houston, TX, where we used to go for brunch. They served it with Blueberry Muffins.