Prepare the Eggs: In a deep dish, whisk the room temperature eggs with vanilla and set aside.
Cream Butter and Ghee: In another deep dish, mix the cold butter and ghee with an electric mixer on low to medium speed until creamy, then gradually add powdered sugar and mix until fluffy.
Combine Eggs: Gradually add the beaten eggs with vanilla to the butter mixture, ensuring they are fully incorporated.
Add Flour and Salt: Add all the flour and salt at once, mixing at a slow speed just until incorporated. Do not overmix.
Forming the Petifour: Shape the dough using a piping bag with specific nozzles (7FT, 6FT, 1M) into small sizes on baking trays.
Baking: Bake in a preheated oven at 180 degrees Celsius, watching closely until they turn golden on both sides.
Storage: Store in a tight container without filling until ready to serve.