Preheat oven to 400°.
Line 2 baking sheets with parchment paper or spray with nonstick spray.
In a separate bowl sift together flour, baking soda and salt, set aside.
With a mixer cream together butter and sugar until light and creamy, about 2-3 minutes.
Beat in eggs one at a time.
Beat in peanut butter and vanilla.
Gradually add dry ingredients to cream mixture until incorporated.
Shape into 1" balls and place on baking sheets 2" apart.
Flatten with a floured tines of a fork.
Bake for about 12 minutes.