Crack the eggs into a bowl and pour the sugar. Beat until the mixture increases its volume.
Then, add the pinch of salt, vanilla, and flour.
When everything is well combined, add the blueberries and mix with a spatula in folding motion, being careful not to break the blueberries.
Pour the mixture into a greased and floured baking pan, trying to make the surface as even as possible. Sprinkle the hazelnuts and sugar on top.
Bake at 350°F for 30-40 min.
