Equipment
Ingredients
Dry Ingredients
- 250 g all-purpose flour
- 10 g baking powder
- 5 g baking soda
- 5 g ground cinnamon
- 2 g ground nutmeg
- 3 g fine sea salt
Wet Ingredients
- 180 ml neutral vegetable oil
- 200 g light brown sugar, packed
- 100 g granulated white sugar
- 3 large eggs, room temperature
- 10 ml vanilla extract
Harvest Produce
- 150 g banana, overripe and mashed
- 150 g carrot, peeled and finely grated
- 150 g courgette, grated
Cream Cheese Frosting
- 400 g full-fat block cream cheese, cool but softened
- 115 g unsalted butter, room temperature
- 200 g icing sugar, sifted
- 5 ml vanilla extract
Nutrition (per serving)
Nutrition is estimated per serving. Nutrients without complete source data are omitted.
Full nutrition
- Calories
- 596 kcal
- Protein
- 6 g
- Carbohydrates
- 64 g
- Fat
- 36 g
- Fiber
- 2 g
- Sugar
- 45 g
- Sodium
- 438 mg
- Saturated Fat
- 14 g
- Trans Fat
- 0 g
- Monounsaturated Fat
- 6 g
- Polyunsaturated Fat
- 1 g
- Cholesterol
- 101 mg
- Potassium
- 230 mg
- Calcium
- 119 mg
- Iron
- 0.9 mg
- Magnesium
- 19 mg
- Phosphorus
- 117 mg
- Zinc
- 0.6 mg
- Vitamin A
- 294 mcg
- Vitamin C
- 4 mg
- Vitamin D
- 0.3 mcg
- Vitamin E
- 0.8 mg
- Vitamin K
- 4 mcg
- Vitamin B6
- 0.1 mg
- Vitamin B12
- 0.2 mcg
- Thiamin
- 0.06 mg
- Riboflavin
- 0.18 mg
- Niacin
- 0.6 mg
- Folate
- 23 mcg
- Water
- 64 g
- Alcohol
- 0 g
Sources: Aggregated Public Data, USDA FoodData Central
Method
Preheat your oven to 175 C or 350 F. Grease two 20cm cake pans and line the bottoms with parchment paper.
Place the grated courgette into a clean kitchen towel. Twist and squeeze firmly over a sink to extract as much excess water as possible. Fluff the squeezed courgette lightly.
In a large mixing bowl, thoroughly whisk together the all-purpose flour, baking powder, baking soda, ground cinnamon, ground nutmeg, and fine sea salt until uniformly blended.
In a separate large bowl or stand mixer, beat the neutral vegetable oil, light brown sugar, and granulated white sugar together. Add the room temperature eggs one at a time, beating well after each addition. Mix in the vanilla extract.
Fold the dry flour mixture into the wet sugar and egg mixture using a spatula. Mix gently just until no dry streaks of flour remain. Do not overmix.
Gently fold the mashed banana, finely grated carrot, and squeezed grated courgette into the batter until evenly distributed.
Divide the batter evenly between the prepared cake pans. Bake at 175 C or 350 F for 30 to 35 minutes.
Allow the cakes to cool in their pans for 15 minutes before turning them out onto a wire cooling rack to cool completely to room temperature.
While the cakes cool, prepare the frosting. In a stand mixer fitted with the paddle attachment, beat the softened butter and cool cream cheese on medium speed until perfectly smooth and creamy. Gradually add the sifted icing sugar and vanilla extract, beating on low speed until combined, then increase to high for one minute to whip.
Once the cake layers are completely cool, place one layer on a serving plate. Spread a generous layer of cream cheese frosting over the top. Place the second layer on top and use the remaining frosting to cover the top and sides of the cake.
Chef's Notes
- Moisture control is the secret to this recipe. Banana, carrot, and courgette all carry water, so aggressively squeezing the courgette guarantees a tender crumb rather than a heavy pudding-like texture.
- Using oil instead of butter in the cake batter coats the flour proteins more effectively, minimizing gluten development and guaranteeing an ultra-moist crumb that stays fresh for days.
- For the ultimate cream cheese frosting, temperature is critical. If your cream cheese gets too warm, it releases water and the frosting will turn into a glaze. Keep the butter at true room temperature, but the cream cheese slightly chilled.
- To elevate the flavor profile, try toasting your ground cinnamon and nutmeg in a dry skillet for 30 seconds until fragrant before mixing them with the dry ingredients. This wakes up the volatile oils in the spices.
Storage
Refrigerator: 5 days — Store in an airtight container to prevent the cake from drying out and the frosting from absorbing fridge odors.
Freezer: 3 months — Unfrosted layers wrap well in plastic wrap and foil. Thaw at room temperature before frosting.
Reheating: Serve at room temperature or slightly chilled. Do not microwave the frosted cake.
Troubleshooting
Cake center is gummy or sank after baking
Cause: Excess moisture from the courgette or underbaking.
Fix: Cannot be fixed once baked. Repurpose into cake truffles or cake pops by crumbling the baked portions with a little frosting.
Prevention: Thoroughly squeeze the grated courgette in a clean kitchen towel before folding into the batter. Always test the cake with a skewer before removing from the oven.
Frosting is runny and slipping off the cake
Cause: Cream cheese was too warm or overbeaten, breaking its emulsion.
Fix: Refrigerate the frosting bowl for 20-30 minutes, then briefly rewhip.
Prevention: Use block cream cheese straight from the fridge and only let it sit for 10-15 minutes before beating. Avoid over-mixing once the sugar is added.
Cultural Context
This recipe takes inspiration from the classic American Hummingbird Cake and Morning Glory muffins of the 1970s. By incorporating the autumnal trio of carrot, courgette, and banana, it reflects a post-war baking tradition where home cooks ingeniously used garden surpluses and natural fruit sugars to create incredibly moist, long-lasting bakes.
