Whisk eggs with both types of sugar until white. Then add vanilla extract.
Add salt, flour and continue beating until incorporated.
At the end, add melted butter and bring the dough to a smooth consistency.
Preheat the oven to 190 °C.
Prepare a baking tin. Today I bake in a silicon mold, so it doesn’t need any preparating. If you are using a metal pan, prepare it as follows: grease each well thoroughly with butter, then sprinkle with flour.
Move the dough into piping bag. Then fill the mold with dough: the blank for each cookie should be filled about halfway, because the dough will increase in volume while baking. You can do the same with the help of two teaspoons too but piping bag works better.
Bake cookies for about 9 minutes until the edges are browned.