Preheat your oven to 350°F (175°C) and prepare an 8-inch baking pan by greasing and lightly flouring it. Gather all your ingredients so everything is ready to go.

In a large mixing bowl, use an electric mixer to beat the butter and ½ cup of the sugar together until the mixture is soft, light, and fluffy. Mix in the vanilla extract and salt. Add the egg yolks and continue beating until the mixture becomes smooth and creamy.

In a separate bowl, whisk together the 1 ½ cups of all-purpose flour and the baking powder. Gradually add the dry mixture to the creamed mixture, alternating with the milk, mixing just until everything is combined.

In a small bowl, toss the blueberries with 1 tablespoon of flour to help prevent them from sinking. Gently fold the floured blueberries into the batter.

In a clean bowl, beat the egg whites using an electric mixer until soft peaks form. Gradually add the remaining ¼ cup of sugar, one tablespoon at a time, and continue beating until stiff peaks form. Carefully fold the whipped egg whites into the batter, being gentle to maintain the airy texture.

Pour the batter into the prepared pan and spread it evenly. Sprinkle the remaining 1 tablespoon of sugar over the top of the batter to create a sweet, crisp crust.

Bake in the preheated oven for about 50 minutes, or until a toothpick inserted into the center of the cake comes out clean.

Let the cake cool slightly on a wire rack, then slice, serve, and enjoy!