Toasted polenta delivers deep corn flavor to this rustic upside-down cake featuring sweet, caramelized oranges.
Orange Polenta Cake
WHY THIS RECIPE WORKS A rustic polenta cake infused with bright citrus flavor and topped with beautiful glazed orange slices makes for a perfect Italian-inspired dessert. We wanted ours to have great corn flavor and a moist, tender crumb. First, we needed to figure out how to incorporate the polenta. Uncooked polenta left our cake with hard bits throughout. Although some recipes call for cooking a batch of polenta and stirring it into the batter, this was a bit labor intensive for what we hoped would be a simple recipe. We found our answer in instant polenta, which required only hydrating to become tender; tasters preferred the richness of polenta hydrated with milk rather than water. Toasting the polenta brought out more depth of flavor. To make an easy yet elegant topping for our cake, we sprinkled some sugar and cornstarch in the bottom of the cake pan and arranged thinly sliced oranges over it. We poured the cake batter directly on top of the oranges, which caramelized beautifully during baking. A bit of orange zest in the cake batter reinforced the fresh citrus flavor. Do not substitute regular or premade polenta for the instant polenta. Be sure to break up any large clumps of the polenta with your fingers before adding it to the batter or the cake will have bits of hard polenta throughout. If using a dark-colored cake pan, start checking the cake for doneness 5 to 10 minutes earlier. Serve this cake as is or with lightly sweetened whipped cream.
1½ cups (8¼ ounces) instant polenta
1½ cups whole milk
2 oranges plus 2 teaspoons grated orange zest
⅓ cup (2⅓ ounces) packed brown sugar
2 teaspoons cornstarch
1 cup (5 ounces) all-purpose flour
1 teaspoon baking powder
½ teaspoon baking soda
3 large eggs
1 cup (7 ounces) granulated sugar
6 tablespoons extra-virgin olive oil
2 teaspoons vanilla extract
1. Adjust oven rack to middle position and heat oven to 350 degrees. Spread polenta in rimmed baking sheet and toast in oven until fragrant, about 10 minutes; transfer to large bowl. Stir in milk and orange zest and let sit until liquid is fully absorbed, about 10 minutes. Using your hands, break polenta into fine crumbs; set aside.
2. Grease 9-inch round cake pan, line with parchment paper, then grease parchment. Combine brown sugar, cornstarch, and ⅛ teaspoon salt in small bowl and sprinkle evenly in bottom of prepared pan. Cut away peel and pith from oranges, then slice crosswise into ⅛-inch-thick slices. Arrange orange slices in single layer over sugar mixture (some slices may overlap slightly).
3. Whisk flour, baking powder, baking soda, and ½ teaspoon salt together in bowl. Using stand mixer fitted with paddle attachment, beat eggs and granulated sugar together on medium speed until pale and tripled in volume, 6 to 8 minutes. Reduce speed to low, slowly add oil and vanilla, and beat until combined. Add polenta crumbs and beat until combined. Add flour mixture in 3 additions until combined, scraping down sides of bowl as needed. Give batter final stir by hand.
4. Pour batter over oranges in pan and spread into even layer. Bake until cake is golden brown and toothpick inserted into center comes out clean, 50 to 60 minutes, rotating pan halfway through baking.
5. Let cake cool in pan on wire rack for 15 minutes. Run paring knife around sides of pan. Place wire rack over pan and, holding rack tightly, invert cake onto rack and let sit until cake releases itself from pan, about 1 minute. Place rack on baking sheet to catch drips. Remove pan; gently scrape off any orange slices stuck in pan and arrange on top of cake. Let cake cool completely, about 2 hours. Serve.