Brown Butter Upside Down Banana Cake

If standard banana bread and classic sticky toffee pudding had a baby, it would be this Brown Butter Banana Upside-Down Cake. We are taking the humble, overripe banana and giving it a massive, nutty, caramelized glow-up.

What makes this cake extraordinary isn’t just that it’s sweet—it’s how the ingredients play off each other to build layers of warmth, fat, acid, and sugar.

The Flavor Pillars

• Nutty, Toasted Brown Butter (Beurre Noisette): When you cook down the butter, the water evaporates and the milk solids toast to a deep hazelnut shade. This introduces a savory, roasted, almost toffee-like backbone into the crumb. It tames the sweetness of the sugars and grounds the entire cake with an earthiness you can’t get from plain melted butter.
• Dual-State Banana Profile: Using bananas in two ways creates incredible depth:
  • Puréed in the batter: Ripe, soft bananas distribute sweet fruitiness through every bite while providing natural moisture and structure.
  • Roasted on top: The semi-ripe banana halves bake directly in the bubbling caramel. They soften into a custard-like texture, taking on a intense banoffee flavor while retaining just enough fruit structure to contrast the soft cake.
• Deep Caramel & Molasses: The sauce on the bottom isn’t made from plain white sugar; it relies on brown sugar. The natural molasses content adds a dark, bittersweet edge to the caramel glaze, surrounding the fruit with a gooey, sticky glaze as it flips.
• Tangy Sour Cream (or Greek Yogurt): Without acid, a banana-caramel dessert can easily tip into overwhelming sweetness. Sour cream acts as a flavor disruptor—its lactic acid brightens the fruit tones and cuts through the heavy fat of the butter, leaving a clean, balanced finish on the palate.
• Warm Cinnamon & Vanilla: A full tablespoon of cinnamon gives the crumb a subtle, spicy kick, while vanilla extract rounds out the sugar notes, making the whole cake smell and taste like a bakery case.

This cake is impossibly moist, extraordinarily tender, and bursting with deep, rich flavor. The secret weapons? A blanket of warm brown sugar caramel, roasted halved bananas, and nutty brown butter running through every single crumb.

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Brown Butter Banana Upside Down Cake

Created by Sue Mun

Makes one, 9×13 inch cake

Ingredients:

For the Caramel Banana Topping:

• 100g unsalted butter
• 190g brown sugar 
• 3-4 semi ripe bananas

For the Brown Butter Banana Cake:

• 360g all purpose flour
• 2 tsp. baking soda
• 1/2 tsp. salt 
• 1 tbsp cinnamon
• 215g unsalted butter (to be browned)
• 100g canola oil
• 250g granulated sugar
• 110g brown sugar
• 2 large eggs
• 2 tsp vanilla extract 
• 220g sour cream or Greek yogurt
• about 6 ripe bananas (530g), puréed smooth

Instructions:

For the Caramelized Banana Topping:

1. Preheat the oven to 350°F (180°C). Grease a 9×13-inch baking pan with pam spray and line the bottom with parchment paper.
2. In a small pan over medium high heat, melt together the butter, and brown sugar. Simmer for about 3 minutes and stir occasionally until the sauce is thick and glossy.
3. Remove the caramel from the heat and pour the sauce into the prepared baking pan. Use a metal offset spatula to spread the caramel evenly in the bottom of the pan.
4. Cut about 3-4 bananas in half lengthwise and place them cut side down on top of the caramel. Set aside while you work on the cake batter.

For the Brown Butter Banana Cake Batter:

1. In a small pan over medium heat, add the butter and cook on high heat to melt the butter. Continue cooking until the butter milk solids have browned and the aroma smells nutty. Try not to burn the milk solids! The color of the milk solids should be golden/light brown. Quickly pour the brown butter to a large mixing bowl and scrape out all of the brown butter from the pot and allow it to cool for 20 minutes at room temperature so its no longer piping hot.
2. In a medium bowl, whisk together the flour, cinnamon, baking soda, and salt. Set aside.
3. Back to the large bowl with the melted but cooled down brown butter, whisk in the sugar and brown sugar. Add in the oil, pureed bananas, eggs, sour cream, and vanilla extract. Whisk until fully combined.
4. Fold in the dry ingredients until just combined until there is no more flour streaks left. Don’t overmix.
5. Pour the batter evenly into the prepared baking pan over the top of the bananas and smooth the top out until it is even and level.
6. Bake the cake for about 60-70 minutes or until a toothpick inserted into the center comes out clean. The center of the cake should spring back when touched. You may need to cover the top of the cake with aluminum foil after the 45 minute mark to ensure that the cake does not burn on top.
7. Cool the cake in the pan for 30-45 minutes then use an offset spatula to release the cake from the pan around the edges of the pan. Then place a cooling rack, a cutting board, or a large enough serving plate on top. Quickly and carefully flip it over and tap the cake out of the pan. Take off the pan and release the parchment paper from the cake.
8. Cool off the cake for another 30 minutes before cutting and serving.