Preheat your oven to 350°F (175°C). Grease and flour a 9-inch flan pan to prevent sticking.

In a bowl, whisk together 3 eggs and 1/2 cup sugar until the mixture is light and fluffy.

Fold in 1/2 cup all-purpose flour, 1/4 cup cornstarch, and 1 tsp baking powder until well combined.

Pour the batter into the prepared flan pan and bake for 12-15 minutes, or until golden brown. Allow it to cool.

In a saucepan, heat 2 cups of milk over medium heat until warm.

In a separate bowl, whisk together 3 egg yolks, 1/3 cup sugar, and 1 tbsp cornstarch.

Slowly whisk in the warm milk to avoid curdling the eggs. Return this mixture to the saucepan and cook over low heat until it thickens.

Stir in 1 tsp vanilla extract for flavor.

Pour the creamy custard over the cooled sponge cake.

Arrange 1 cup strawberries, 1/2 cup blueberries, and 1/2 cup raspberries on top of the custard.

In another saucepan, dissolve 1 tbsp sugar and 1 tsp cornstarch in 1/2 cup water. Simmer until thickened.

Brush this mixture over the fruits to give them a glossy finish.

Chill the flan in the refrigerator for at least 1 hour before serving.