Low Sugar Banana Cake

Total time1 hr 55 min

Prep time20 min

Cook time35 min

Ripe mashed bananas bring natural sweetness and moisture to this snackable sheet cake, while a touch of sour cream and cinnamon keep the crumb soft and warmly spiced. The batter comes together in one bowl with a simple flax egg for binding, then bakes into an even, tender layer that springs back to the touch. A smooth, fluffy frosting gets swept over the top once the cake cools, finishing it off in classic bakery style. Sliced into squares, it's an easy make-ahead treat for potlucks, lunchboxes, or an afternoon coffee break. This one is a solid pick for anyone keeping an eye on added sugar, without giving up that classic banana cake flavor and texture.

About Fig

Fig is a food discovery app that helps you find foods and recipes that fit your dietary needs. Whether you have food allergies, intolerances, or follow a specific diet, Fig makes it easy to eat with confidence.

Learn more →

Ingredients

12 servings

For the flax egg

For the cake

3 medium very ripe bananas (about 1 ½ cups mashed)
½ cup unsalted butter, softened
¾ cup granulated sugar
Chef's tip
Use the same volume. Baking behavior varies by blend: some brown faster or stay softer, while others brown less. Follow the package's baking guidance and start checking a few minutes early.
¼ cup packed light brown sugar
Chef's tip
Use the same volume. Brown-sugar replacements vary in moisture, spread, and browning, so follow the package's baking guidance and start checking a few minutes early.
½ cup sour cream
1 tsp vanilla extract
2 cups all-purpose flour
1 tsp baking soda
½ tsp baking powder
½ tsp salt
½ tsp ground cinnamon
¼ cup milk

For the frosting

½ cup unsalted butter, softened
2 cups powdered sugar, sifted
Chef's tip
Follow the package's conversion to powdered sugar. In frosting or glaze, add liquid gradually - replacements can absorb it differently.
2 tbsp milk
½ tsp vanilla extract
1 pinch salt

Instructions

1
Preheat the oven to 350°F (175°C). Grease a 9x13-inch baking pan and line the bottom with parchment paper.
2
In a small bowl, stir together the ground flaxseed and 3 tbsp water until combined. Set aside for 5 minutes, until the mixture thickens to a gel-like consistency.

Want the full recipe?

Create a Fig account for step-by-step instructions, access to our full recipe library, and more!