Light and fluffy rum buttercream frosting made with spiced rum, this is perfect for eggnog cookies and anything you'd like to add a hint of rum to! If you prefer not to use alcohol, we've added a note on using rum extract instead.
Ingredient Notes and Substitutions
- Spiced rum: if you don’t want to use rum in the buttercream, add rum extract by the ¼ teaspoon until you are happy with the flavour. You could mix in a touch of cinnamon and cloves to make it spiced.
- Salt: only add this if you're using unsalted butter. If using salted butter, omit the extra salt.
- Make it dairy-free: follow the recipe for our vegan vanilla frosting and a tablespoon or two of spiced rum (to taste). You will need a little extra icing sugar to make it thick enough.
Step 1: beat the butter until light and fluffy, then beat in the vanilla and salt.
Step 2: sift in the icing sugar.
Step 3: beat again until creamy, then scrape down the sides and add the rum to taste.
Step 4: mix between each addition until the buttercream tastes how you'd like, then serve.
- Beat the butter well: this is a bit part of what makes for a nicely fluffy, pale buttercream. Mix the butter before adding any sugar for the best results.
- Make it by hand: if you don't have an electric mixer or hand mixer, you can make frosting with a whisk or wooden spoon and plenty of elbow grease. Just keep beating until it looks as pictured.
- Add to taste: the amount of rum you add will depend on your preference, so make sure to add it in small amounts and keep tasting.
How to Store
Storage: transfer the frosting to a sealed container and store in the fridge for up to a week. It will harden a bit in the fridge, so depending on use, you'll probably need to bring it back up to room temperature.
Freezing: keep rum buttercream in an airtight container in the freezer for up to three months. Thaw overnight in the fridge and beat again before use.
Does alcohol split buttercream?
Alcohol like rum can cause buttercream to split. The trick is to beat it in slowly, adding small amounts at a time, and mixing between each addition.
What makes buttercream more stiff?
If your buttercream is too runny, you can either add more icing sugar to thicken or refrigerate until it reaches the consistency you'd like. Chilling it is better if you don't want a too-sweet frosting.
Can you over whip buttercream?
Yes. You want to beat buttercream until the sugar is dissolved. Test it by rubbing some between your fingers – if it feels gritty, it hasn't been mixed enough. But if you over whip, the buttercream can start to reduce in volume and may even separate.
If you make this Rum Frosting recipe or any other frosting recipes on the Baked Collective, please take a moment to rate the recipe and leave a comment below. It’s such a help to others who want to try the recipe. For more baking, follow along on Instagram, TikTok, and YouTube.
Rum Buttercream Frosting
- Electric hand or standing mixer with whisk attachment
- Large mixing bowl
- Measuring cups and spoons
- 1 cup butter at room temperature
- ½ teaspoon vanilla extract
- ⅛ teaspoon salt if using unsalted butter
- 2 cups powdered sugar
- 1-2 tablespoons spiced rum to taste
- Add the butter to a large mixing bowl and beat on medium-high speed until light and fluffy, about 1 to 2 minutes. Add the vanilla and salt and mix to combine.1 cup butter, ½ teaspoon vanilla extract, ⅛ teaspoon salt
- Sift the powdered sugar through a sieve into the bowl then mix to a thick frosting.2 cups powdered sugar
- Add the spiced rum by the teaspoon, mixing well between each addition, until you are satisfied with the flavour. I usually use around 2 tablespoons of rum.1-2 tablespoons spiced rum
- Use the frosting now or refrigerate, covered, for up to a week.