This Keto Peanut Butter Frosting is creamy and full of rich peanut butter flavor. It’s a quick and easy to make sugar-free frosting that whips up in minutes and tastes amazing on cakes, cupcakes or cookies.

❤️ Why You’ll Love This Peanut Butter Frosting Recipe

• Smooth and creamy texture
• Rich peanut butter flavor
• Easy to make with just a handful of ingredients
• Sugar-free and kid friendly
• Spread over your favorite cake or cupcakes

When it comes to frostings, some are just too sweet and some are too thin to hold to decorating. I’ve tested this recipe enough times to know it’s the one I’ll reach for when I need a depending frosting that has the perfect balance of sweet and nutty.

It’s quick to make with pantry staples, whips up in minutes, and doesn’t have the gritty texture you sometimes get with sugar free frostings. The peanut butter flavor pairs beautifully with everything from cakes and cupcakes to cookies. It’s even delicious off the spoon too (I won’t tell if you don’t!)

If you’re looking for another delicious keto frosting recipe, be sure to check out my Cream Cheese and Chocolate frosting recipes.

🛒 Ingredients for Sugar-Free Peanut Butter Frosting

• Mascarpone cheese: Makes the frosting creamy and stable without being too heavy.
• Unsalted grass-fed butter: Softens to whip smoothly and adds rich flavor.
• No sugar-added peanut butter: The star ingredient, giving nutty richness.
• Heavy cream: Adds fluff and helps adjust consistency.
• Monk fruit/allulose, powdered: Keeps it smooth and sweet without sugar.
• Vanilla extract :Rounds out the flavor with a little warmth.

*Exact measurements are listed in the recipe card below.

🥣 Recommended Tools

• Mixing bowl
• Hand mixer
• Piping bag

🔪 How to Make Keto Peanut Butter Frosting

Add the mascarpone cheese and butter together in a bowl and whip using a hand mixer.

Add in most of the heavy cream (reserving about a tablespoon) and sweetener.

Then add in the peanut butter and vanilla extract.

Continue whipping until smooth and creamy.

Add more of the heavy cream, if needed, to get your desired consistency.

Add the frosting to a piping bag fitted with the tip of your choice.

If you don’t have a piping bag, a zip lock bag with the tip cut off will work too.

☑️ Storage Instructions

Fridge: Store leftover frosting in an airtight container for up to 5 days. Bring to room temperature before using.

Freezer: You can also freeze it in a sealed container for up to 2 months. Thaw it overnight in the fridge, then rewhip before spreading.

🍴 Tasty Ways to Use This Peanut Butter Frosting

• Cupcakes: Pipe tall swirls on chocolate, vanilla, or even pumpkin cupcakes.

• Cakes: Spread between layers or over the top of Keto chocolate or vanilla cakes.

• Cookies: Use as a sandwich filling between these Keto Peanut Butter Cookies or spread a dollop on top.

• Brownies: Frost a pan of these Keto Avocado Brownies for a rich peanut butter chocolate combo.

• Bars: Spread some over these Keto White Chocolate Blondies or cookie bars before slicing.

• Frosting dessert board: Serve in a bowl alongside these Keto Vanilla Wafers, Butter Pecan Cookies or any of your favorite sweet Keto dippable snacks.

💡 Tips

• Make sure your butter and mascarpone are softened before mixing for a lump-free frosting.
• Use an electric mixer to whip air into the frosting, which makes it light and fluffy.
• Start with less cream and add more as needed until you get the consistency you like.
• Always sift powdered sweetener before adding to avoid clumps.
• Taste and adjust sweetness, since peanut butter brands vary in flavor intensity.
• Chill the bowl and beaters for 10 minutes if your kitchen is warm, so the frosting doesn’t soften too quickly.

🔄 Substitutions and Additions

• Chocolate chips: Stir in sugar free chocolate chips for a fun crunchy texture.

• Almond: Swap vanilla extract for almond extract for a different flavor twist.

• Cocoa: Fold in a tablespoon of cocoa powder for a peanut butter chocolate version.

• Peanut butter: Use crunchy peanut butter instead of creamy for a more rustic spread.

• Piping: Pipe the frosting tall on cupcakes and sprinkle with crushed peanuts.

• Topping: Add a drizzle of melted sugar free chocolate over frosted cupcakes for a bakery-style finish.

Is Peanut Butter Keto?

Peanuts are indeed a legume and it’s debatable whether they are considered Keto friendly. Because they are high in fat and fiber, this makes them an exception to the rule in most cases.

However, when you’re selecting a Keto friendly peanut butter, you want to look for one that says, ” All Natural,” and also indicates there is no sugar added.

How Carbs in Peanut Butter?

The amount of carbs in peanut butter greatly depends on the brand. All natural, no sugar added peanut butter will have between 4 to 5 net carbs per 2 tbls. sized portion.

Why Is My Frosting Runny?

It usually means the butter or mascarpone was too soft. Chill it for 10 minutes and whip again.

Can I Make This Frosting Ahead of Time?

Yes, just store it in the fridge and let it soften before using. Rewhip if needed.

What If My Frosting Is Too Sweet?

You should not have that problem with this recipe. But you can always add a little more peanut butter or mascarpone to mellow the sweetness.

Do I Need to Refrigerate Frosted Cakes?

Yes, because the recipe contains cream and mascarpone, it’s safest kept in the fridge.

🍽️ More Keto Peanut Butter Recipes

• Low Carb Peanut Butter Mousse
• Keto Peanut Butter Cookies
• Chocolate Peanut Butter Truffle Fats Bombs
• Chocolate Keto Cupcakes with Peanut Butter Frosting

If you’d like to know more about baking on Keto, this article, Keto Baking Made Easy, is loaded with tips and info that you’ll find helpful. You might also check out my Keto Sweet Treats eBook that has 50 amazing Keto dessert recipes, all with color pics, macros and more! I’m offering it at 50% off when you subscribe to my free weekly emails here.

*Originally published on September 22, 2018, updated on September 19, 2025 with improvements to the recipe, new photos, new recipe information and helpful tips.