Caramelized Blueberry Upside Down Mini Cakes

If you ask me, upside down cakes are one of the most fun desserts to make.

These mini blueberry versions are perfect for when you want something sweet but not too heavy. Fresh berries create a pretty purple top (which is actually the bottom!) while the cake underneath stays soft and moist.

I love how the fruit gets slightly jammy during baking, mixing with the brown sugar to make its own natural sauce. The individual portions mean everyone gets their own little cake with the perfect fruit-to-cake ratio.

It’s a laid-back dessert that feels special enough for company but simple enough for a weeknight treat.

What Kind of Blueberries Should I Use?

While this recipe calls for frozen blueberries, you can actually use either fresh or frozen ones with great results. Frozen blueberries are super convenient and often more economical, plus they’re picked at peak ripeness which means they’re packed with flavor. If you’re using fresh blueberries, look for ones that are firm, deep blue in color, and have a slight silvery frost on the skin – this is a natural protective coating that indicates freshness. For frozen berries, check the package to make sure there aren’t any ice crystals or clumps, which could mean they’ve been thawed and refrozen. Just remember that frozen berries will release more liquid as they cook, which actually works well in an upside-down cake format.

Options for Substitutions

Here are some helpful substitutions you can try with these mini cakes:

• Frozen blueberries: Fresh blueberries work perfectly here, or try other berries like raspberries, blackberries, or even pitted cherries. Just make sure they’re not too wet – pat them dry if using fresh fruit.
• All-purpose flour: You can use cake flour for an even lighter texture – just add 2 extra tablespoons per cup. Self-rising flour works too, but skip the baking powder and salt if you use it.
• Milk: Any milk works here – whole, 2%, or plant-based options like almond or oat milk. Buttermilk gives a nice tang, but reduce the baking powder to 3/4 teaspoon and add 1/4 teaspoon baking soda.
• Light brown sugar: Dark brown sugar can be used instead – it’ll give a deeper molasses flavor. Regular white sugar works too, but you’ll miss some of that caramel note.
• Unsalted butter: If using salted butter, just skip the added salt in the recipe. For dairy-free versions, use melted coconut oil or a plant-based butter substitute in equal amounts.

Watch Out for These Mistakes While Baking

The trickiest part of making upside-down cakes is the flip – if you wait too long after baking, the caramelized topping can stick to the pan and ruin your beautiful presentation, so be sure to turn these mini cakes out while they’re still warm (about 5-10 minutes after removing from the oven). Using frozen blueberries straight from the freezer is actually better than fresh ones, as they release less juice during baking and help maintain the cake’s structure, but make sure to arrange them in a single layer without overcrowding. The butter temperature matters more than you might think – the butter for the cake batter needs to be properly softened at room temperature (not melted) for the right texture, while the butter for the topping should be cold to create those perfect caramel pockets. To prevent the dreaded soggy bottom (which becomes the top), avoid over-mixing the batter once you add the flour – mix just until the ingredients are combined, as overmixing can lead to dense, tough cakes.

What to Serve With Blueberry Upside Down Cakes?

These sweet little cakes are perfect for dessert and pair wonderfully with a scoop of vanilla ice cream or a dollop of fresh whipped cream on top. If you’re serving them for brunch, try adding a side of Greek yogurt and a drizzle of honey – the tanginess of the yogurt works really well with the sweet blueberries. For an extra special touch, you could make a quick blueberry sauce with any leftover berries to spoon over the top, or serve them alongside your morning coffee or afternoon tea. Keep in mind these mini cakes are pretty rich on their own, so simple accompaniments work best!

Storage Instructions

Keep Fresh: These mini cakes are best enjoyed the day they’re made, but you can keep them in an airtight container at room temperature for up to 2 days. The blueberry topping might make them a bit more moist over time, but they’ll still taste great!

Refrigerate: If you want them to last a bit longer, pop them in the fridge in a sealed container for up to 5 days. Just remember to place wax paper between layers to prevent them from sticking together.

Freeze: These little cakes freeze surprisingly well! Wrap each cake individually in plastic wrap, then place them in a freezer bag. They’ll stay good for up to 3 months. When you’re craving one, just thaw it overnight in the fridge.

Warm Up: To bring back that fresh-baked taste, warm up your cake in the microwave for about 15-20 seconds. The blueberries will get slightly jammy again, making it taste almost like it just came out of the oven!

Preparation Time	15-20 minutes
Cooking Time	20-24 minutes
Total Time	35-44 minutes
Level of Difficulty	Medium

Estimated Nutrition

Estimated nutrition for the whole recipe (without optional ingredients):

• Calories: 800-900
• Protein: 10-15 g
• Fat: 40-45 g
• Carbohydrates: 100-110 g

Ingredients

For the blueberry base:

• 2 tbsp unsalted butter, chilled and cut into 12 pieces
• 1/4 cup light brown sugar, packed
• 2 cups frozen blueberries

For the cake batter:

• 1/3 cup unsalted butter, at room temperature
• 1/2 cup white sugar
• 1/4 cup packed light brown sugar
• 1 large egg, at room temperature
• 2 tsp vanilla extract
• 1 1/4 cup all-purpose flour
• 1 tsp baking powder
• 1/4 tsp salt
• 1/2 cup milk

Step 1: Prepare Muffin Tin with Butter and Sugar

• 2 tbsp unsalted butter, chilled and cut into 12 pieces
• 1/4 cup light brown sugar, packed

Preheat your oven to 350°F (175°C).

Spray all 12 cups of a muffin tin with nonstick cooking spray to prevent sticking.

Divide the 2 tablespoons of chilled, cubed unsalted butter and the 1/4 cup of packed light brown sugar evenly among the muffin tins, placing one butter cube and a portion of sugar into each cup.

Step 2: Add Blueberries to Muffin Tins

• 2 cups frozen blueberries

Evenly distribute the frozen blueberries among the 12 muffin tins, adding them directly on top of the butter and brown sugar mixture in each cup.

There’s no need to thaw the blueberries beforehand.

Step 3: Prepare the Cake Batter

• 1/3 cup unsalted butter
• 1/2 cup granulated sugar
• 1/4 cup light brown sugar, packed
• 1 egg
• 1 teaspoon vanilla extract
• 1 1/2 cups all-purpose flour
• 1 1/2 teaspoons baking powder
• 1/4 teaspoon salt
• 1/2 cup milk

In a stand mixer fitted with the paddle attachment, add 1/3 cup butter, 1/2 cup granulated sugar, and 1/4 cup light brown sugar.

Cream together for about 3 minutes until the mixture becomes lighter in color and fluffy.

Add the egg and vanilla, mixing until fully combined.

In a separate bowl, combine the flour, baking powder, and salt.

Gradually mix the dry ingredients into the creamed mixture, alternating with milk, until everything is just combined.

I find that alternating the dry and wet ingredients gives the batter a smoother texture.

Step 4: Assemble and Bake the Cakes

• Cake batter from Step 3
• Blueberry and sugar base from Steps 1 and 2

Spoon the prepared batter from Step 3 evenly into the muffin tins, filling them on top of the blueberries.

Smooth the tops if needed.

Place the muffin tin in the preheated oven and bake for 20-24 minutes, or until the cakes are golden brown and set.

Step 5: Cool, Release, and Serve Cakes

Let the cakes cool in the muffin tin for about 5 minutes.

Run a knife gently along the sides of each cake to help loosen them, then use a spoon to carefully lift each cake and invert it onto a plate so the blueberry mixture is on top.

Repeat with the remaining cakes.

Serve warm, and I love topping these with a scoop of ice cream for extra deliciousness!