Gluten-Free Caramelized Apple Upside-Down Cake

The presentation is half the fun, but the taste and texture are also what makes an upside-down cake stellar. A layer of apples and sugar is arranged on the bottom with cake batter spread over top. While the cake bakes, the sugars and fruit caramelize on the bottom. While warm, the cake is flipped right-side-up to unveil the fruit sitting right on top, while the juices and caramelized sugars ever-so-slowly seep into the perfectly-baked cake below. 

Unlike a cake baked with the fruit on top of the batter, an upside-down cake does not run the risk of the fruit sinking into the cake or the juicy fruit causing an underbaked or too moist cake.

Tips for apple upside-down cake

Use a cake pan with high sides

For this cake, you need a cake pan with at least 2-inch high sides. With a layer of apples underneath, this cake is quite tall. As the cake batter has its initial rise, it will fill the entire 2-inch pan. As the apples cook down, they will create space so it won't overflow.

Line the bottom with parchment paper

To ensure your sticky caramelized apples don't stick to the pan and get left behind when you turn out the cake, line your cake pan with a round of parchment paper. Once flipped, you can carefully peel off the parchment paper to reveal the warm tender apples.

Flip shortly after baking

If you wait too long to flip the cake, the caramelized sugars and fruit will begin to set up and harden, causing them to stick to the pan. Instead, let the cake cool only 5-10 minutes before flipping. 

Serve warm or at room temperature

This cake is delicious served warm or after it has cooled completely. To serve warm, let it cool 30 minutes before slicing so the crumb sets up. Alternatively, you can heat fully cooled slices for 10 seconds in the microwave and serve with a scoop of vanilla ice cream. 

Flours for Gluten-Free Apple Upside-Down Cake

When making gluten-free cake, I prefer using a homemade blend of flours to enhance the flavors of the cake I'm making. This gluten-free apple upside-down cake uses a blend of oat flour, sweet rice flour, tapioca flour, and teff flour.

Alternatively, if you'd prefer to use a pre-made blend, you can sub out all the flours by weight (239g) along with the xanthan gum with Bob's Red Mill 1-to-1 all-purpose gluten-free flour blend.

Bob's Red Mill gluten-free oat flour: Oat flour adds lightness and structure to the fluffy crumb. It keeps the cake super moist, but not overly dense. If you don't have oat flour, you can make your own by grinding gluten-free rolled oats in a blender or food processor until fine, then sifting out any larger pieces. 

Sweet rice flour: Sweet rice flour is necessary for the chewy texture of this cake. Also called "Mochiko, sweet rice flour is distinctly different from white rice or brown rice flour. Rather it is the same flour used to make mochi, and as such, its stickiness helps to bind the cake together, creating chewiness like a classic cake recipe. It's gluten-free baking's secret weapon. 

Bob's Red Mill tapioca flour: Tapioca flour adds chewiness and helps mimic the fluffiness of a classic cake. It adds just a bit more softness and loftiness to the crumb. 

Bob's Red Mill teff flour: Teff flour is such a warm flavorful flour that's the perfect pairing for a spiced cake. In this cake, teff flour is the flavor driver. You don't need a lot to get the flavor benefits. As a powdery fine flour, it bakes up soft and fluffy with rich toffee notes that accentuate the caramelized apple topping. 

Xanthan gum: Without xanthan gum, the batter is thin and seeps up under the apples and the cake bakes up dense.

What kind of apples for baking

The best apples for cakes are crisp apples that hold up against the heat of baking like Granny Smith and Honeycrisp. These are always what are reach for when I'm making warm gluten-free apple crisp or this family recipe for gluten-free german apple cake.

Granny Smith apples have a natural tartness that balances dessert nicely, while Honeycrisp apples are crisp and firm with a nice combination of sweet and tart. 

How to flip an upside-down cake

While upside-down cakes are simple to bake, paying close attention to the timing of flipping the cake is crucial. Cool the cake just 5-10 minutes after it comes out of the oven before flipping. Cooling any longer than 10 minutes will result in the caramelized sugars and fruit firming up and the fruit will stick to the bottom. 

To flip, start by running a thin knife around the outside of the cake. Place a wire rack over the top of the cake pan and have a plate or baking sheet nearby to catch drips. Using oven mitts to hold the cake pan and the wire rack tightly together, flip the cake over and set the wire rack onto the plate/baking sheet. Carefully and slowly lift the cake pan to release the cake. Peel off the parchment paper.

Spoon any remaining caramel from the pan over the top, and if any apple pieces are stuck to the pan, carefully arrange them back on the cake. Let cool for at least 30 minutes before slicing and serving.