Lemon Yogurt Soda Cake

Lemon zest and juice give this small square cake a bright citrus flavor, while yogurt keeps the crumb moist. Baking soda works with the acidic ingredients to provide lift, so the batter should go into a fully heated oven soon after mixing. A light lemon glaze is optional and should be added only after the cake has cooled.

Recipe details

• Yield: One 8-inch cake, 9 servings
• Prep time: 15 minutes
• Bake time: 28 to 34 minutes
• Cooling time: 45 minutes
• Total time: about 1 hour 30 minutes

Equipment

• 8-inch square metal baking pan
• Parchment paper
• Two mixing bowls
• Fine grater, citrus juicer, whisk, and spatula
• Wire rack and instant-read thermometer or wooden pick

Ingredients

• 1 1/2 cups (180 g) all-purpose flour
• 3/4 teaspoon baking soda
• 1/2 teaspoon baking powder
• 1/2 teaspoon fine salt
• 2 large eggs, at room temperature
• 3/4 cup (150 g) granulated sugar
• 1 cup (240 g) plain whole-milk yogurt, at room temperature
• 1/3 cup (80 ml) neutral oil
• 2 tablespoons (30 ml) fresh lemon juice
• 1 tablespoon finely grated lemon zest
• 1 teaspoon vanilla extract
• 1/2 cup (60 g) confectioners’ sugar, optional
• 1 tablespoon fresh lemon juice, optional, for glaze

Method

1. Heat the oven to 350°F (175°C). Lightly oil the pan and line the bottom and two sides with parchment, leaving an overhang.
2. Whisk the flour, baking soda, baking powder, and salt in a medium bowl. Make sure no small clumps of baking soda remain.
3. In a large bowl, rub the granulated sugar and lemon zest together with your fingertips until fragrant. Whisk in the eggs, yogurt, oil, 2 tablespoons lemon juice, and vanilla until smooth.
4. Fold the dry mixture into the wet mixture just until the flour disappears. Immediately spread the batter evenly in the prepared pan.
5. Bake for 28 to 34 minutes, until the center springs back, a wooden pick comes out without wet batter, and the center reaches at least 160°F (71°C). Cool in the pan for 15 minutes, then lift the cake onto a wire rack and cool completely.
6. For the optional glaze, whisk the confectioners’ sugar with 1 tablespoon lemon juice. Drizzle over the cool cake and let it set for 15 minutes before cutting into nine squares.

Helpful notes

Zest only the yellow outer layer; the white pith underneath tastes bitter. Measure the soda accurately and distribute it through the flour to avoid alkaline-tasting spots. Once wet and dry ingredients meet, do not leave the batter waiting, because its initial bubbles begin forming immediately. A sunken middle often indicates underbaking or an oven door opened too early.

Regular plain yogurt gives the intended moisture. To use Greek yogurt, combine 3/4 cup (180 g) Greek yogurt with 1/4 cup (60 ml) milk. Lime zest and juice can replace lemon in equal quantities. Melted, cooled butter can replace the oil, though the refrigerated cake will feel firmer. The glaze may be omitted for a less sweet finish.

Serve the cake plain or with berries. Let it cool fully before covering. Store unglazed cake airtight at room temperature for up to 2 days; refrigerate glazed cake and any longer-kept portions for up to 5 days. Freeze unglazed squares for up to 2 months, then thaw them while wrapped to limit moisture loss.