Brownies are supposed to be gooey inside while crunchy and crusty on the outside!.
Preheat oven to 400°F and line an 8-inch square metal baking pan with foil. Chop chocolate coarsely. Melt butter and chocolate in the microwave using low settings (or in a double boiler). Stir until smooth. Stir in sugar, vanilla and salt. Add eggs one at a time, followed by flour. Stir until well combined. Add walnuts and mix again. Scrape batter into prepared pan and bake for 22 - 24 minutes. When brownies are done remove from oven and place immediately in the freezer. If you don't have space in your freezer, make an ice bath instead. Allow to cool completely then remove pan and cut brownies into squares.