Make a ganache and allow it to cool:
Bring 1/3 cup heavy cream to barely boiling in microwave or on stovetop
Add 1-1/2 cups semi-sweet chocolate chips
Allow to sit for a minute in the hot cream. Stir with a spatula until smooth and there are no lumps of chocolate left. You may have to microwave it just a bit to continue the melting.
In stand mixer, whip 1 lb. (four cubes) real butter for a long time.
Add:
Cooled ganache
5 cups powdered sugar
1 Tbl. vanilla
Mix all together, scraping down the sides occasionally. Continue to mix for a long time until it is fluffy! Use a rubber spatula to stir it a bit to get out the air bubbles before frosting.
Freezes well! After freezing, allow it to come to room temperature. Re-whip to light and fluffy again before using.
