Banana Cake with Cream Cheese Frosting

Before you start

Banana cake and banana bread share a flavor but not a texture. Bread is dense and moist, built to slice; this cake is creamed, so the butter and sugar are beaten with air before the eggs go in, and buttermilk plus baking soda give it a fine, springy crumb that can stand up as two layers under frosting.

The bananas decide most of the outcome. Use fruit with heavily freckled or fully brown skins and measure it by weight after mashing, because three bananas can weigh anything from 280 to 420 grams. Too much banana makes the layers gummy and heavy in the middle; too little leaves the cake bland. Let the layers cool completely before frosting, since cream cheese frosting slides off a warm cake.

Ingredients

• Cake300 g (2½ cups, spooned and leveled) all-purpose flour
• 1 tsp baking soda
• 1 tsp baking powder
• ¾ tsp fine salt
• ½ tsp ground cinnamon — optional
• 170 g (¾ cup) unsalted butter — softened
• 200 g (1 cup) granulated sugar
• 55 g (¼ cup packed) light brown sugar
• 3 large eggs — room temperature
• 2 tsp vanilla extract
• 340 g (about 1½ cups, from 3 to 4 bananas) mashed very ripe banana
• 180 ml (¾ cup) buttermilk — room temperature
• Frosting225 g (8 oz) full-fat brick cream cheese — cool but soft, not from a tub
• 115 g (½ cup) unsalted butter — softened
• 300 g (2½ cups) powdered sugar — sifted
• 1 tsp vanilla extract
• 1 pinch fine salt

Method

1. Heat the oven to 175°C (350°F) with a rack in the center. Grease both pans, line the bottoms with parchment circles and grease the parchment.
2. Whisk the flour, baking soda, baking powder, salt and cinnamon in a bowl. In a second bowl, mash the bananas with a fork until mostly smooth with a few small lumps, then weigh out 340 g.
3. Beat the butter, granulated sugar and brown sugar on medium-high for 3 to 4 minutes, until noticeably paler and fluffy. Scrape the bowl.
4. Add the eggs one at a time, beating about 20 seconds after each, then beat in the vanilla. The mixture may look slightly curdled; it will smooth out when the flour goes in.
5. Stir the mashed banana into the buttermilk. On low speed, add the dry ingredients in three parts, alternating with the banana mixture in two parts, beginning and ending with flour. Mix only until no dry streaks remain.
6. Divide the batter evenly between the pans, about 700 g each, and smooth the tops. Bake for 28 to 32 minutes, until the tops spring back when pressed and a toothpick in the center comes out with a few moist crumbs but no wet batter.
7. Cool the layers in the pans for 15 minutes, run a thin knife around the edges and turn them out onto a rack. Peel off the parchment and cool completely, about 1 hour.
8. For the frosting, beat the butter until creamy, add the cream cheese and beat just until smooth, about 30 seconds. Add the powdered sugar, vanilla and salt and beat on low, then medium, only until fluffy. Long beating thins cream cheese frosting.
9. Set one layer top-side down on a plate, spread about a third of the frosting over it, add the second layer top-side down and cover the top and sides with the rest. Refrigerate for 20 minutes if the frosting feels soft before slicing.

Tips for success

• Bananas ripen fastest in a closed paper bag. Peeled overripe bananas freeze well; thaw them and use the liquid that seeps out, since it is mostly banana sugar and flavor.
• Weigh the batter into the pans so the layers bake in the same time and stack level.
• Press a finger into the cream cheese before you start. It should give easily but still feel cool; warm cream cheese gives runny frosting.

Substitutions

Buttermilk

Use 120 g plain yogurt thinned with 60 ml milk. The crumb stays tender and slightly tangy. Plain milk works only if you cut the baking soda to ½ tsp and raise the baking powder to 2 tsp.

Two round pans

Bake in one 23 x 33 cm (9 x 13 in) pan for 30 to 35 minutes and frost only the top. The cake is a little flatter but easier to serve.

Cream cheese frosting

Brown butter frosting suits banana well: brown 115 g butter, cool it until soft, then beat with 250 g powdered sugar and 2 to 3 tbsp milk.

Variations

Banana walnut cake

Fold 75 g toasted chopped walnuts into the finished batter and press more around the base of the frosted cake.

Banana sheet cake

Bake in a 23 x 33 cm pan as in the substitutions, then frost the cooled cake right in the pan.

Troubleshooting

Dense, gummy band near the bottom

Too much banana or overmixing after the flour went in. Weigh the mashed fruit and stop mixing as soon as the flour disappears.

Layers domed and cracked

The oven runs hot or the pans are dark. Check with an oven thermometer, and wrap the pans in damp cake strips for flatter tops.

Frosting is too soft to hold on the sides

The cream cheese was too warm or the frosting was overbeaten. Chill it for 20 to 30 minutes, then stir briefly by hand rather than beating it again.

Cake tastes flat, not very banana-y

The bananas were not ripe enough. Wait until the skins are mostly brown, and keep the cinnamon light so it does not mask the fruit.

Storage

Because the frosting contains cream cheese, keep the cake covered in the refrigerator for up to 4 days and do not leave it out more than 2 hours. Let slices stand 20 to 30 minutes before serving for a softer crumb. Unfrosted, well-wrapped layers freeze for up to 2 months.

Safety notes

Do not taste the raw batter; it contains raw flour and raw egg. Contains wheat, egg and milk, plus tree nuts if you add walnuts.