Mandarin Polenta Cake: A Moist Gluten-Free Yogurt Upside-Down Cake

Gluten-Free Mandarin Polenta Yogurt Cake With an Upside-Down Fruit Topping

This mandarin polenta cake pairs a tender, yogurt-rich crumb with a bright layer of fruit and brown sugar. Use fine-ground cornmeal, sometimes labeled fine polenta, rather than coarse polenta or instant polenta. Fine cornmeal softens as the cake bakes, especially when mixed with yogurt, while coarse grains can leave the finished cake unpleasantly gritty.

For a reliable gluten-free cake, combine the cornmeal with almond flour and a certified gluten-free all-purpose flour blend. The mandarins sit on a simple butter-and-sugar layer at the bottom of the pan, then become the topping when the cake is turned out.

Ingredients

Makes one 9-inch cake, about 8 servings

Mandarin topping

• 3 medium mandarins, preferably seedless
• 4 tablespoons (57 g) unsalted butter
• ⅓ cup (67 g) packed light brown sugar

Cake

• 1 cup (150 g) fine-ground cornmeal or fine polenta
• ¾ cup (75 g) almond flour
• 1 cup (120 g) certified gluten-free all-purpose flour blend
• 2 teaspoons baking powder
• ½ teaspoon fine salt
• ½ cup (113 g) unsalted butter, softened
• ¾ cup (150 g) granulated sugar
• 2 large eggs, at room temperature
• ¾ cup (180 g) plain Greek yogurt, preferably full-fat
• 1 tablespoon finely grated mandarin zest
• 1 teaspoon vanilla extract

Prepare the pan and fruit

Heat the oven to 350°F (175°C). Grease a 9-inch round cake pan. Line the bottom with parchment paper, then grease the parchment as well. A springform pan can leak the fruit’s syrup, so a standard cake pan is the safer choice.

Peel the mandarins and remove as much of the white pith as you can without breaking the fruit apart. Slice each mandarin crosswise into rounds about ¼ inch thick. Pick out any seeds and blot the cut surfaces gently with a paper towel. If the rounds are especially large, cut them in half so they fit neatly in the pan.

Melt the topping butter and stir in the brown sugar. Spread the mixture across the parchment-lined bottom. Arrange the mandarin rounds over it in a snug, single layer, overlapping them slightly where needed. The fruit may shrink as it bakes, so a close arrangement helps keep the finished top covered.

Mix and bake the cake

Whisk the cornmeal, almond flour, gluten-free flour blend, baking powder, and salt in a bowl. Breaking up any clumps now makes it easier to mix the batter without overworking it later.

In a separate large bowl, beat the softened butter and granulated sugar until creamy, about 2 minutes. Add the eggs one at a time, beating after each. Mix in the yogurt, mandarin zest, and vanilla. The mixture may look slightly curdled after the yogurt goes in; that is usually fine.

Add the dry ingredients and mix on low speed, or fold by hand, just until no dry patches remain. The batter will be thick. Spread it gently over the mandarins, taking care not to shift the fruit. Smooth the surface.

Bake for 45 to 55 minutes, until the center springs back when lightly pressed and a toothpick inserted into the cake comes out with a few moist crumbs but no wet batter. If the top begins to brown too quickly, lay a piece of foil loosely over the pan for the last part of baking.

Set the pan on a rack and leave the cake to cool for 12 to 15 minutes. Run a thin knife around the edge. Place a serving plate upside down over the pan, hold both firmly, and invert them together. Lift the pan straight up, then peel away the parchment. If a mandarin slice sticks to the paper, ease it off with a small spatula and return it to its place while the topping is still warm.

Let the cake cool before slicing. The syrup sets as it stands, and the crumb becomes easier to cut.

Choosing cornmeal and keeping the crumb tender

Look for cornmeal labeled fine or fine-ground. Some packages call it polenta, but the texture is what matters. Coarse polenta is intended to retain distinct grains, so it is a poor fit for this cake. Instant polenta is precooked and may behave differently from ordinary cornmeal; unless the package specifically describes it as fine-ground cornmeal, choose another product.

Cornmeal absorbs moisture more slowly than wheat flour. The yogurt supplies moisture and a gentle tang, while almond flour helps keep the crumb soft. For the smoothest texture, let the batter stand for about 10 minutes before spreading it in the pan. This gives the cornmeal a brief chance to hydrate. Avoid substituting a larger amount of cornmeal for the almond or gluten-free flour; that can make the cake dense and gritty.

Greek yogurt gives the batter body and contributes to a moist polenta cake. If using regular plain yogurt, drain off excess liquid or use a little less, since thinner yogurt can make the batter loose. Avoid flavored or sweetened yogurt, which changes both the sweetness and the texture.

Gluten-free ingredient checks

Cornmeal and almond flour are naturally gluten-free ingredients, but packaging and processing still matter. For a gluten-free cake, check that the cornmeal, almond flour, baking powder, and flour blend are labeled gluten-free. Milling and packing facilities may handle wheat, and cross-contact can be a concern for people with celiac disease.

Use a flour blend intended for baking, ideally one containing a binder such as xanthan gum. If the blend does not contain a binder, add the amount recommended on its package for cakes. Different blends vary, so follow the manufacturer’s guidance rather than adding an arbitrary amount. Also check that the yogurt, vanilla, and any other packaged ingredients meet the needs of the person who will eat the cake.

Clean the work surface, pan, utensils, and mixer attachments before baking if avoiding cross-contact is necessary. A gluten-free ingredient list alone does not make a kitchen free of gluten.

How to keep the fruit topping intact

The parchment is the most useful safeguard when releasing the cake. Greasing the pan helps, but mandarin juice and caramelized sugar can cling to bare metal. Make sure the parchment covers the entire base and lies flat beneath the topping.

Let the cake rest for 12 to 15 minutes before turning it out. Invert it too soon and the cake may be fragile; wait until it is completely cold and the syrup can firm up enough to hold the fruit in place. If the pan has cooled for a long time and the cake seems stuck, set the bottom of the pan in warm water for a few seconds, then loosen the edge and invert.

If a slice of fruit shifts during release, reposition it while the topping is warm. Small imperfections are easy to hide when the cake is served, and the flavor does not depend on a perfectly even pattern.

Serving and storing

Serve the cake at room temperature, on its own or with a spoonful of lightly sweetened yogurt. Because the fruit topping is moist, cover leftovers and refrigerate them within 2 hours. The cake keeps for about 3 days in the refrigerator. Let slices sit at room temperature briefly before serving, or warm them gently until just soft. The topping may become a little looser after refrigeration.

For the cleanest slices, use a sharp knife and wipe it between cuts. If the cake is chilled, the topping will be firmer and the crumb less tender, so allowing it to warm slightly improves both.