Combine flour, salt and baking soda in a bowl. Place chopped walnuts and toffee bits in a different bowl. In a third bowl or using a stand mixer, beat together the butter and sugar. Once the mixture is fluffy, add the eggs, one at a time, followed by the vanilla.
Mix in the Heath Bar mixture and the flour mixture, alternating one third at a time, until well blended. Place the dough in the refrigerator for 30-60 minutes to chill.
Preheat oven to 350°F. On cookie sheets lined with parchment paper or my personal favorite, Silpat, spoon out the cookie dough in small 1-inch diameter balls (about a teaspoon of dough each). Place dough balls 3 inches away from each other on the cookie sheets - the dough will spread as they bake.
Bake for 10-12 minutes, until the edges begin to brown. Remove from oven and let cool for a few minutes. Transfer cookies to a wire rack to cool completely.
Recipe by In Good Taste at http://ingoodtaste.kitchen/heath-bar-cookies/