Whisk together flour, baking soda, pudding mix and salt in a medium bowl and set aside. 

Cream together butter and sugar in a bowl until light and fluffy. Add eggs and vanilla extract, and beat until well combined.

Slowly add the flour mixture, beating until just combined after each addition. 

Refrigerate dough for at least 4 hours.

Preheat the oven to 350?. Bake 8-12 minutes or until the edges have started to lightly brown and the tops are set