In a large bowl, beat the butter, cream, vanilla, and salt together with an electric mixer on medium-high speed until smooth, about 1 to 2 minutes.
Reduce the mixer speed to medium-low, slowly add the confectioners' sugar and beat until incorporated and smooth, about 4 to 5 minutes. Increase the mixer speed to medium-high and beat until the frosting is light and fluffy, about 5 to 10 minutes.
For Coffee Frosting:
Add instant espresso to the butter mixture before beating.
For Peppermint Frosting:
Add peppermint extract to the butter mixture before beating.
For Orange Frosting:
Add the orange juice and grated fresh orange zest to the butter mixture before beating.
For Almond Frosting:
Add almond extract to the butter mixture before beating.
For Coconut Frosting:
Add coconut extract to the butter mixture before beating.