In a large bowl, beat butter and shortening together until smooth and creamy (about 2 minutes).
Gradually add powdered sugar, one cup at a time, mixing on low until incorporated.
Add vanilla, almond extract, and salt.
Slowly add heavy cream, a little at a time, until frosting is fluffy and smooth. Beat on medium-high for 3–5 minutes.
If too stiff → add more cream. If too soft → add more powdered sugar.