In a large bowl, beat heavy cream until stiff peaks form.
In a smaller bowl, combine cake mix, protein powder, sweetened condensed milk, and sprinkles. Slowly fold the cake mix mixture into the whipped cream, then pour into a freezer safe container. Top with more sprinkles if desired.
Cover the container and freeze for 6 hours or overnight.
If you don't have protein powder or don't want to use it, you can substitute in 1/3 cup of cake mix.