Prep your pan and oven. Heat the oven to 350°F (175°C). Line the bottom of an 8-inch (20 cm) round cake pan or springform with parchment. Lightly grease the sides and dust with flour, then tap out the excess.

Whisk dry ingredients. In a bowl, whisk 1 cup (125 g) all-purpose flour, 2 tablespoons cornstarch (optional), 1½ teaspoons baking powder, and ¼ teaspoon fine salt. Set aside.

Beat the eggs and sugar. In a large bowl, beat 3 large eggs and ¾ cup (150 g) granulated sugar with a hand mixer or stand mixer on medium-high for 3–4 minutes, until pale, thick, and ribbony. This step builds volume, so don’t rush it.

Mix the wet ingredients. In a separate small bowl, whisk ¾ cup (180 g) plain Greek yogurt, ¼ cup (60 ml) neutral oil, 1½ teaspoons vanilla extract, and the zest of 1 lemon until smooth.

Combine gently. With the mixer on low, add the yogurt mixture to the egg mixture in a slow stream. Mix just until combined—no need to overwork.

Fold in the dry ingredients. Sift the dry mixture over the batter. Use a spatula to fold with light strokes, turning the bowl as you go. Stop as soon as you no longer see dry flour. Overmixing will deflate the batter.

Pan and bake. Pour the batter into the prepared pan and smooth the top. Bake for 28–35 minutes, until the top is golden and springs back, and a toothpick comes out with a few moist crumbs.

Cool properly. Let the cake cool in the pan for 10 minutes. Run a knife around the edge, then turn it out onto a rack. Peel off the parchment and let it cool completely.

Finish and serve. Dust with powdered sugar or top with fresh berries. Slice with a sharp knife. Enjoy as is or with a spoonful of yogurt or whipped cream.