This rosemary plum upside-down cake starts the way all good upside-down cakes do: melted butter and dark brown sugar in the pan, ripe plums fanned over, and a buttermilk batter poured on top. The rosemary is unexpected and exactly right — savory against all that caramelized fruit. Flip it warm; the reveal is the best part.
A Showstopping Cake with a Secret Ingredient!
Get ready to fall in love with the ultimate late-summer dessert! This Rosemary Plum Upside-Down Cake is a true showstopper. Imagine sinking your fork into a tender, buttermilk-infused cake, topped with a glistening layer of jammy, caramelized plums. The secret? A whisper of fresh rosemary that adds an unexpected, sophisticated floral note, beautifully balancing the sweetness of the fruit. It’s rustic, elegant, and surprisingly simple to create. The dramatic flip at the end is pure kitchen magic, revealing a stunning, jewel-toned topping that’s guaranteed to impress.
Ingredients
• 8 tablespoons / 113g (4 oz) unsalted butter, melted
• 1/2 cup / 110g (3.9 oz) packed dark brown sugar
• 1 teaspoon (5 ml / 0.2 fl oz) finely chopped fresh rosemary leaves
• 4 to 5 ripe sweet plums, about 1 lb / 450g, pitted and cut into chunks
• 1 cup / 240ml buttermilk
• 2 large eggs
• 1/2 cup / 100g (3.5 oz) granulated sugar
• 2 cups / 250g (8.8 oz) all-purpose flour
• 1 teaspoon (5 ml / 0.2 fl oz) baking soda
• 1/4 teaspoon (20 ml / 0.7 fl oz) salt
Instructions
1. Preheat the oven to 350°F / 175°C. Liberally grease a 9-inch round cake pan or cast-iron skillet with half of the melted butter. Sprinkle the brown sugar and rosemary evenly over the bottom. Arrange the plum chunks in a single, even layer over the sugar and set the pan aside.
2. In a large bowl, whisk the remaining melted butter, buttermilk, eggs, and granulated sugar together until light and foamy.
3. In a separate bowl, whisk together the all-purpose flour, baking soda, and salt.
4. Gradually add the dry to the wet , stirring with a spatula only until the batter is well incorporated. Be careful not to overmix; a few lumps are okay.
5. Carefully pour and spread the batter over the plums in the pan, using the spatula to ensure it’s evenly distributed.
6. Bake for 50 to 60 minutes, or until the top of the cake is golden brown and a toothpick inserted into the center comes out clean.
7. Let the cake cool in the pan on a wire rack for exactly 5 minutes. Run a thin knife around the edge of the pan to loosen the cake.
8. Place a large serving plate on top of the cake pan. With confidence and oven mitts, quickly flip the pan and plate together. Lift the pan away; the cake should release onto the plate. If any fruit sticks to the pan, simply lift it off and place it back on the cake. Serve warm, perhaps with a scoop of vanilla ice cream.
Nutritional Information
• Please note that the following is an estimate per serving (assuming 8 servings) and can vary based on the specific used.
• Calories: 410 kcal
• Carbohydrates: 65g
• Protein: 6g
• Fat: 15g
• Sugar: 40g
Pro Tips
• & Variations
• Use a Cast-Iron Skillet: For a superior, deeply caramelized fruit topping, bake this cake in a 9-inch cast-iron skillet instead of a standard cake pan.
• The 5-Minute Flip: Let the cake cool for just 5 minutes before inverting. This is the sweet spot where the caramel is fluid enough to release but the cake is set enough to hold its shape.
• Seasonal Swaps: No plums? This cake is fantastic with sliced apples, pears, blackberries, or pitted cherries. For a Pear and Almond version, swap rosemary for 1/4 cup (960 ml) chopped almonds and half the flour for 1/2 cup (480 ml) ground almonds.
• Don’t Overmix: Stir the batter only until the flour is just incorporated. A few lumps are okay and are the secret to a more tender cake.
FAQ
Q: Can I make this plum upside-down cake vegan
A: Yes, you can easily adapt this recipe to be vegan. Use a plant-based butter substitute for the unsalted butter. For the buttermilk, mix 1 cup (240 ml) of unsweetened plant-based milk (like soy or almond) with 1 tablespoon (15 ml / 0.5 fl oz) of lemon juice and let it sit for 5-10 minutes. Replace the two large eggs with two flax eggs (2 tbsp / 30 ml ground flaxseed mixed with 6 tbsp water) or 1/2 cup (480 ml) of unsweetened applesauce.
Q: Is buttermilk always vegetarian
A: Yes, traditional and cultured buttermilk are both vegetarian as they are dairy products without any meat derivatives. If you don’t have any, you can make a quick vegetarian substitute by adding one tablespoon of lemon juice or white vinegar to one cup of regular milk and letting it curdle for 5-10 minutes before using.
Q: How should I store this vegetarian plum cake
A: Store the cake in an airtight container at room temperature for up to 2 days. For longer storage, you can refrigerate it for up to 5 days. The caramelized plum topping will become more moist in the fridge, but the cake will still be delicious. Gently reheat a slice before serving if you prefer it warm.
Q: Can this recipe be made gluten-free
A: To make this a gluten-free vegetarian cake, substitute the all-purpose flour with a high-quality 1-to-1 gluten-free baking flour blend that contains xanthan gum. The baking time may vary slightly, so use the toothpick test to check for doneness. The rest of the ingredients are naturally gluten-free.
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Rosemary Plum Upside-Down Cake
Ingredients
Method
- Preheat the oven to 350°F / 175°C. Liberally grease a 9-inch round cake pan or cast-iron skillet with half of the melted butter.
- Sprinkle the brown sugar and rosemary evenly over the bottom.
- Arrange the plum chunks in a single, even layer over the sugar and set the pan aside.
- In a large bowl, whisk the remaining melted butter, buttermilk, eggs, and granulated sugar together until light and foamy.
- In a separate bowl, whisk together the all-purpose flour, baking soda, and salt.
- Gradually add the dry to the wet , stirring with a spatula only until the batter is well incorporated. Be careful not to overmix; a few lumps are okay.
- Carefully pour and spread the batter over the plums in the pan, using the spatula to ensure it's evenly distributed.
- Bake for 50 to 60 minutes, or until the top of the cake is golden brown and a toothpick inserted into the center comes out clean.
- Let the cake cool in the pan on a wire rack for exactly 5 minutes. Run a thin knife around the edge of the pan to loosen the cake.
- Place a large serving plate on top of the cake pan. With confidence and oven mitts, quickly flip the pan and plate together. Lift the pan away; the cake should release onto the plate. If any fruit sticks to the pan, simply lift it off and place it back on the cake.
- Serve warm, perhaps with a scoop of vanilla ice cream.
- Seasonal Swaps: No plums? This cake is fantastic with sliced apples, pears, blackberries, or pitted cherries. For a Pear and Almond version, swap rosemary for 1/4 cup (960 ml) chopped almonds and half the flour for 1/2 cup (480 ml) ground almonds.
- Don't Overmix: Stir the batter only until the flour is just incorporated. A few lumps are okay and are the secret to a more tender cake.
