Empty both cans of frosting in a stand mixer fitted with a paddle attachment. Pour in ½ cup of powdered sugar. Mix on low speed until powdered sugar is incorporated then whip on medium speed for 30 seconds.
Turn the mixer off, lift the paddle attachment and see if the frosting is stiff and thick. If it still seems a little on the soft side add in the additional ¼ cup of powdered sugar. Repeat step one with mixing until stiff.
Using a piping bag place the 2D piping tip in the bag (for rosettes). Fill your piping bag ¾ of the way and begin piping on rosettes. Once frosting is almost done, repeat by filling bag and piping on more. Do this until your cake is full of rosettes.
Notes
Some times you just need an easy short cut and that’s why I’m sharing my “hack” for how to pipe on canned frosting. You just need two ingredients, a piping bag and piping tip and you are in business!