Mom's Best Recipes
Recipe

Peanut Butter Icing

A fluffy, creamy peanut butter icing that’s sweet, salty, and ridiculously spreadable. Ready in about 10 minutes and perfect for cakes, cupcakes, brownies, and sandwich cookies.

Author By Matt Campbell
4.8
A slice of chocolate cake topped with a thick swirl of creamy peanut butter icing on a light stoneware plate on a bright kitchen table

If chocolate and peanut butter are your comfort-food love language, this is the icing you want on speed dial. It is creamy, fluffy, and unapologetically peanut buttery, with just enough salt to keep the sweetness from going full sugar overload.

I built this recipe to be weeknight friendly and bakery reliable. It spreads smoothly, pipes neatly, and it is easy to tweak depending on whether you want it soft and swoopy or firm enough for sharp cupcake swirls.

Bowls of powdered sugar, creamy peanut butter, softened butter, vanilla extract, milk, and a pinch of salt arranged on a clean kitchen counter with a mixing bowl

Why It Works

  • Big flavor fast: Peanut butter and vanilla do most of the work, and a pinch of salt makes it taste like more than the sum of its parts.
  • Stable texture: Butter gives structure while peanut butter brings richness, so the icing holds up on cakes and cupcakes without feeling heavy.
  • Adjustable on purpose: You control thickness with milk and powdered sugar, so it works for spreading, piping, or sandwiching cookies.
  • Not gritty: A quick sift and proper mixing order keeps it smooth.

Pairs Well With

Storage Tips

Refrigerator: Store icing in an airtight container for up to 5 days for best quality. Press plastic wrap directly onto the surface if you want extra protection from drying out.

Freezer: Freeze for up to 2 months for best quality in a freezer-safe container. Thaw overnight in the fridge.

To reuse: Bring to room temp, then re-whip for 30 to 60 seconds. If it feels stiff, beat in 1 to 2 teaspoons milk. If it feels loose, add 2 to 3 tablespoons powdered sugar.

Common Questions

Can I use natural peanut butter?

You can, but it is less predictable. Natural peanut butter can separate and make the icing either oily or too soft. If you use it, stir it very well until fully smooth, then start with less milk and add only if needed.

Does this icing crust?

It can form a light skin on the outside after an hour or two, but it does not usually crust hard like a classic American buttercream with lots of sugar. It stays creamy and sliceable.

Why is my peanut butter icing too thick?

Usually it is cold butter or too much powdered sugar. Let it sit at room temperature for 10 minutes, then beat again. Add milk 1 teaspoon at a time until it loosens up.

Why is it too soft or runny?

Your butter may be too warm, or the kitchen is hot. Chill the bowl for 10 to 15 minutes, then re-whip. If it still feels loose, add powdered sugar in 1/4 cup increments.

Can I make it chocolate peanut butter icing?

Yes. Beat in 1/3 cup unsweetened cocoa powder (sifted). You will likely need an extra 1 to 2 tablespoons milk to keep it spreadable.

How much does this recipe frost?

This makes about 3 cups. Plan on 12 cupcakes for tall bakery-style swirls, 18 to 24 cupcakes for a simple, lighter layer, or enough to fill and frost a two-layer 8-inch cake with modest layers.

I used to think peanut butter frosting was one of those things you only got at a bakery, the kind that’s perfectly swirled and somehow tastes like a peanut butter cup without being cloying. Then I started chasing that exact vibe at home and realized the secret is not fancy ingredients. It is the little stuff: soft butter, a real pinch of salt, and the confidence to adjust the texture as you go. This icing is my go-to when I want something cozy and bold, and honestly, when I want people to stop talking mid-bite.