Preheat your oven to 350°F (175°C).

Sift together the all-purpose flour and cornstarch five times.

Combine 3/4 cup of granulated sugar with a pinch of salt.

Begin beating your egg whites on medium speed until foamy, then add cream of tartar, vanilla extract, and lemon zest.

Slowly add the remaining 3/4 cup of granulated sugar to the whipped egg whites while beating on high speed.

Toss the blueberries with a tablespoon of flour to prevent sinking, then fold them into the egg white mixture.

Pour half of the batter into an ungreased tube pan, followed by half of the flour-dusted blueberries.

Bake for 40 to 43 minutes, or until golden brown and springs back when touched.

Once baked, invert the cake onto a cooling rack.

Prepare the glaze by whisking together lemon juice and powdered sugar.

Drizzle the glaze over the cooled cake and garnish with lemon slices.