Dust the blueberries with cornstarch.
Preheat the oven to 350°F/160°C. Grease a 10-inch springform pan generously with cooking spray and set aside.
Mix flour, baking powder, and lemon zest in a small bowl.
Cream the butter and sugar at high speed in a stand mixer (2-3 minutes). Add egg yolks one at a time and continue mixing for an additional 2 minutes.
Add yogurt and continue mixing. Sift the flour mixture into the batter, then add vanilla extract and lemon juice. Mix gently but thoroughly.
In a separate bowl, beat egg whites until soft peaks form.
Using a spatula, gently fold the beaten egg whites into the batter.
Stir well until everything is fully combined. Scrape down the sides of the mixing bowl.
Pour half of the batter into the greased cake pan and spread evenly. Top with half of the blueberries. Spread with the remaining batter, then evenly place the remaining blueberries over the top.
Tap pans on the work surface to eliminate any large air bubbles.
Bake at 350℉/177℃ until a tester inserted into the center comes out clean – about 50-55 minutes. Transfer to a wire rack.
Let the cake rest in the pan for about 20 minutes, then remove the ring and let it cool. Don’t be tempted to remove it before then.
Dust with optional powdered sugar.