Preheat your oven to 375 degrees. Grease an 8x8 pan with non-stick cooking spray
In a large bowl sift together flour, salt, and baking soda.
Using a stand mixer or hand mixer, cream the butter and sugar until fluffy. Add the eggs, one at a time, mixing well after each egg. Mix in the vanilla. Reduce the mixer speed to low and slowly add the flour mixture to the butter mixture and mix just until combined.
Spread into prepared baking dish.
Bake for 10-15 min, until light golden brown or until a toothpick comes out clean
Cool completely.