Put the butter (250g) and peanut butter (250g) into a large bowl and beat (by hand or using an electric mixer on a slow speed) until fully combined and soft.
Add the icing sugar (250g) a tablespoon at a time and beat on a low speed until fully combined.
Your buttercream is now ready to serve. If you find it's become a little soft then simply pop it into the fridge until it has firmed up a little.
Makes enough for 12 cupcakes or for a thin filling and covering on a 20cm 2-layer round cake
I used my peanut buttercream to decorate my delicious chocolate cupcakes. If you fancy trying something a little different you can find my full collections of cupcakes here as well as all my other buttercream flavours.
NOTE - If you're using natural peanut butter you'll find quite a lot of oil at the top. You want to ensure that you drain as much of the oil away from the peanut butter as possible or you'll find that your buttercream will become too soft.
Calories: 311kcal | Carbohydrates: 20.1g | Protein: 5.4g | Fat: 22.9g | Saturated Fat: 10.8g | Fiber: 1.5g | Sugar: 19g
Any nutritional information provided is the estimated nutritional information per serving. Please refer to my guide to Charlotte’s Lively Kitchen nutritional information if you would like to learn more about how this is calculated.