Preheat oven to 325°F

Whisk egg whites until foamy about 4 min

Add 2 tbsp sugar and beat until stiff, set aside

Place egg yolks, 1/2 cup sugar,water and Vanilla and whisk until pale and fluffy, about 5-7 min

Add melted butter slowly and mix another minute

Sift blueberries and flour into eggs and fold in gently

Add lukewarm milk and beat until well incorporated

Gently fold in egg whites

Pour batter into a greased 8x8 pan. Bake for 45-55 min until top is golden brown but center is slightly jiggly

Cool 3 hours. Top with powdered sugat and blackberries