Recipes - Desserts and Sweets - Protein Buttercream Frosting

Protein Buttercream Frosting

YIELD: Macros reflect 40 gram serving of 3:1 ratio recipe
KETO DIET PLANS: Classic Keto, Modified Keto, Modified Atkins, Low Glycemic Index, and MCT Oil


This frosting is unique because it is a great source of protein & fat rather than carbohydrate like typical frostings. Since baked items usually are higher in carbohydrate, this is a great way to meet protien requirments and increase fat while still being able to decorate cakes and cupcakes.  This is listed as a “food item” in the KetoDietCalculator in the fat category as “Buttercream Frosting”. Each ratio is a separate item.

4:1 Ratio:

  • Reduce the protein powder to 23g


2:1 Ratio

  • Increase the protein powder to 47g


A few tips:

  • If using a high quality butter like Kerrygold, the final frosting will have a more yellow color. Generic grocery store butter will have a lighter color, almost white, when finished.
  • Since this recipe contains butter, it must be refrigerated for storage.
  • It will melt in high temperature or if left sitting in direct sunlight due to the butter.
  • Use a pastry bag for writing and making designs.
  • Use a drop of natural food coloring to make different colors.
  • May be sutible for hiding medication.


113g unsalted butter, room temperature
31g whey protein isolate powder, NOW Foods brand
50g water
4g pure extract, any flavor
sweetener of your choice, powdered varieties preferred over granular
tiny pinch of salt


1Mix the protein powder, water, extract, sweetener, and salt together very well. This will make a thick paste.
2Use electric beaters or a stand mixer with a whisk attachment to "cream" the butter until it has lightened in color.
3Scrape the sides of the bowl once and continue to cream the butter.
4With the mixer at low speed, slowly pour the protein powder mixture into the creamed butter. Continue mixing at a low speed until all the protein powder mixture is incorporated. Make sure you scrape the bowl. Increase the beater speed to high and continue to mix. This process will take at least 5 minutes total. You will know it is ready when it has turned from light yellow in color to almost white.
5Now you are ready to decorate! Weigh the needed amount of icing and use exactly as regular frosting.