Unwrap the three cakes, removing the parchment paper. Level the tops of the cakes so they are flat.
Fill a piping bag fitted with an 8–10 mm round tip) with frosting.
Place one layer of cake on the cake stand, pipe a rim of frosting, and fill with half the cranberry filling, smoothing with a spatula.
Pipe frosting over top to completely cover the rim and filling, smoothing with a spatula again.
Top with a second layer of cake and repeat the rim, filling, and frosting step.
Top with the third layer of cake. Dirty ice (crumb coat) the outside of the cake.
Chill the cake 30 minutes to set the layers before proceeding to frost the outside with the rest of the frosting.
Use your spatula to smooth and add texture to the sides of the cake, and top the cake with sugared cranberries just before serving.