What you need
This frosting uses a handful of basic ingredients. It makes enough to frost the top of a 9-inch cake or about 12 cupcakes.
- 1/2 cup (115 g) unsalted butter, softened
- 1 small very ripe banana, mashed until completely smooth (about 1/4 cup)
- 1 teaspoon lemon juice
- 1 teaspoon vanilla extract
- Pinch of salt
- 2 1/2 to 3 cups (300 to 360 g) powdered sugar, sifted
The basic three components of most icings are sugar (usually powdered), a fat or liquid to make it spreadable, and a flavoring. Here the butter and banana do double duty.
How to make it
- Beat the butter on medium speed for 2 to 3 minutes until pale and creamy.
- Stir the mashed banana with the lemon juice and vanilla in a small bowl. The banana should have no lumps, so mash it with a fork or blend it.
- Add the banana mixture and salt to the butter and mix until combined.
- Add the powdered sugar a little at a time on low speed so it does not fly out of the bowl.
- Beat on medium for 2 to 3 minutes until fluffy and spreadable.
- Taste, and adjust with a little more sugar or a splash of lemon.
Use it on completely cooled cakes.
Preventing browning
Bananas darken when exposed to air, and the frosting may turn a little tan or gray over time. A small amount of lemon juice slows this a little, but does not stop it. For the nicest look, frost the cake the day you plan to serve it and keep it covered. The color change does not affect safety in a short time, but the flavor and look are best fresh.
Fixing runny or stiff frosting
- Too runny: add powdered sugar a spoonful at a time, or chill the bowl for 15 minutes.
- Too stiff: add a few drops of milk or banana puree.
- Grainy: sift the powdered sugar and beat longer.
- Too sweet: add a pinch of salt or a little more lemon juice.
Frosting without butter
If you want a frosting without butter, there are a few options:
- Cream cheese: beat 8 oz (225 g) softened cream cheese with mashed banana, vanilla and powdered sugar. It must be kept chilled.
- Shortening or parve margarine: replace the butter with the same amount. The parve banana cake uses this approach.
- Whipped coconut cream: chill a can of full-fat coconut milk overnight, whip the thick part with powdered sugar and a little mashed banana.
A simple glaze for banana bread
For a lighter finish, whisk 1 cup (120 g) powdered sugar with 1 to 2 tablespoons milk and 1/2 teaspoon vanilla until pourable. A little lemon juice or a pinch of cinnamon gives variety. Drizzle over the cooled loaf. The same method appears in our two-ingredient icing recipe, which covers fixes for glazes that are too thin or too thick.
What to put it on
- A plain cake like our gluten-free banana cake
- Chocolate or spice cupcakes
- The hazelnut banana cake, instead of a chocolate glaze
- Graham cracker sandwiches or brownies
Storage
Frosted cakes with butter-based frosting can sit at room temperature for a day if the room is cool, but refrigerate for longer storage. Bring chilled frosting to room temperature and beat again before using. Plain frosting keeps in the fridge in an airtight container for a few days.
FAQ
Can I use banana extract? Yes, a little can boost flavor, but start with a few drops.
Can I make it ahead? It’s best made on the day, but you can refrigerate it and rewhip.
Can I use frozen bananas? Thaw and drain excess liquid first, and mash well.