I found this recipe on Pintrest and altered it to be RNY friendly. I don't have exact nutrition information.

Ingredients

• 1 Pkg Pillsbury sugar-free Yellow Cake Mix
  
• 2 Pk sugar free Orange Gelatin
  
• 1 Pk Sugar Free vanilla Instant pudding
  
• 1 Cup Fat Free/Skim Milk
  
• 2 Large eggs
  
• 2 Tsp Vanilla Extract
  
• 1 Tub Fat Free/Sugar Free Whipped Topping
  

Directions

Bake the cake as directed in a 9x13" pan. Let cake cool completely. Poke holes in cooled cake. Mix 1 package orange gelatin dessert with 1 c. boiling Water and 1 c. cold water. Pour over cake. Cover and refrigerate for 4 hours. Mix pudding mix with cold milk the other package of orange gelatin dessert and vanilla. Beat by hand with a whisk until thickened. Fold in the whipped topping. Frost the cake with the pudding mixture.

This sounds so good!

It got a lot of rave reviews and no one knew it was sugar free/low cal. I tried a small piece. Not too shabby if I say so myself. And it wasn't super sweet which I liked, not like normal cake frosting.