In a bowl, mix together flour and salt. Set aside.
In a larger bowl, mix together egg and sugar. Add butter and vanilla extract and mix thoroughly. Slowly add flour into wet ingredients and mix until cookie dough forms.
Cover bowl with plastic and chill in the refrigerator for a minimum of 2 hours.
Once the dough has chilled, remove from the refrigerator.
Line a baking sheet with parchment paper and preheat oven to 350 degrees.
Roll cookies into one-inch spheres, and place them on the lined baking sheet, at least 2 inches apart. (about 15 could fit on one pan, so it is suggested to bake in separate batches).
Using the back of a rounded teaspoon, lightly press a cavity in the center of each cookie.
Bake for 7 minutes and remove from oven.
Use the same teaspoon to press into each cavity even further (careful it’s hot!)
Place back into oven and bake for an additional 4-5 minutes. Remove from oven and allow to cool on a wire rack.