Greek Orange Cake (Portokalopita)

Ingredients

• 1 pound (454 g) thin phyllo dough, preferably number 4
• 2 medium oranges or 3 clementines (about 12 ounces / 340 g total), preferably unwaxed and organic
• ⅔ cup (160 ml) freshly squeezed orange juice
• ⅔ cup (160 ml) water
• ⅔ cup (133 g) granulated sugar
• 1 cinnamon stick
• 1¼ cups (250 g) granulated sugar
• 4 large eggs, at room temperature
• 1 cup (230 g) thick plain whole-milk Greek yogurt, at room temperature
• 1 cup (240 ml) neutral oil
• 1½ teaspoons pure vanilla extract
• 1¼ teaspoons baking powder
• ½ teaspoon baking soda
• ½ teaspoon ground cinnamon
• ¼ teaspoon fine sea salt
• Thick whole-milk Greek yogurt or vanilla ice cream, for serving (optional)

Instructions

1. Dry the phyllo: Separate and loosely crumple the phyllo sheets onto two rimmed baking sheets. Leave them uncovered at room temperature for several hours, or bake at 250°F (120°C) for about 45 to 60 minutes, turning occasionally, until completely dry and brittle. Cool, then crush into small flakes.
2. Place the whole oranges or clementines in a saucepan, cover generously with water, and bring to a boil. Lower the heat and simmer for about 1 hour, until very tender. Drain, cool, cut into pieces, and remove any seeds.
3. Make the syrup: Combine the orange juice, water, sugar, and cinnamon stick in a saucepan. Bring to a boil, stirring to dissolve the sugar, then simmer for 5 minutes. Remove from the heat and cool completely; discard the cinnamon stick.
4. Center a rack in the oven and preheat to 350°F (175°C). Coat a 9-by-13-inch baking pan with baker’s spray or lightly oil it.
5. Put the cooked oranges and the 1¼ cups sugar in a food processor and process until smooth. Add the eggs and process until pale and well blended.
6. Add the yogurt, oil, and vanilla and process until smooth. Sprinkle in the baking powder, baking soda, ground cinnamon, and salt, then pulse just until evenly combined.
7. Transfer the batter to a very large bowl. Add the dried phyllo flakes a few handfuls at a time, folding well after each addition so every piece is saturated and no dry clumps remain.
8. Spread the mixture evenly in the prepared pan. Bake for 45 to 55 minutes, until deeply golden, firm in the center, and a tester inserted in the middle comes out clean.
9. Set the hot cake on a rack. Use a skewer to poke holes all over the surface, then slowly ladle the completely cooled orange syrup over the hot cake, pausing so it can soak in evenly.
10. Cool to room temperature, cover, and refrigerate for at least 6 hours—preferably overnight—so the syrup fully settles into the phyllo.
11. Cut into 12 squares and serve chilled or at cool room temperature, with thick Greek yogurt or vanilla ice cream if desired.