Place the butter in a stand mixer fitted with the whisk attachment. You can also use a medium to large-sized bowl with an electric mixer.
Whip the butter on high speed until pale and fluffy, 1-2 minutes. To avoid splatter, start with a lower speed and slowly increase.
With the mixer off, add 3/4 cup of maple syrup and 1/4 teaspoon salt. Whip until the ingredients are evenly combined. Taste and add more maple syrup and/or salt if desired.
Transfer to an airtight storage container of your choice (I used a small Weck mason jar). Serve immediately, or store in the refrigerator for several months.
Notes
Any type of salt will work in this recipe except for super coarse options like pretzel salt.