Beat the eggs with a mixer and add the powdered sugar to them, then add the butter and vanillas.
Turn the mixer off and start stirring with a fork, while adding flour. Knead the dough with your hands.
Put it for 1-2 hours in the fridge, then take out for 15 min. at room temperature.
Fill the pastry bag and spray out biscuits onto a tray with baking paper.
Bake at moderate temperature until pink.