In a large bowl, cream butter. Gradually add confectioner's sugar at 1/2 cup a time. After each cup has been added, increase speed of mixer to incorporate more air. Once all sugar has been added, add in vanilla bean paste and mix well.
Gradually add half and half, one tablespoon at a time until frosting reaches a spreadable consistency.
Spread frosting on top of cooled cookies or cookie cake.
Decorate with sprinkles (optional) and serve!
If you do not have Vanilla Bean Paste, you can simply substitute vanilla extract.