In the bowl of a stand mixer using the paddle attachment, cream the room temperature butter until light and fluffy on medium-high speed. Scrape down sides of bowl, add softened cream cheese, and beat on low speed until thoroughly combined and no lumps remain; 1 minute. Add in vanilla extract, zest, and salt. Blend until fully incorporated.
Sift in the Redpath® Icing Sugar in three parts. After each addition, cream on low speed until smooth. After all the sugar is added, increase speed to medium and beat for 1 minute; do not overmix.
Carefully fold in the chilled roasted cranberries. If necessary, blot off any excess syrup that may have formed with paper towels.
Place the cream cheese frosting into the fridge to chill and firm up; 30 minutes.
Use as a filling for cakes, cupcakes, or whoopie pies.