• 3/4 cup butter
• 6 (1-ounce) squares unsweetened chocolate
• 1 3/4 cups granulated sugar
• 4 large eggs
• 1 1/2 teaspoons vanilla extract
• 1/2 teaspoon salt
• 1 1/2 cups all-purpose flour

Directions:

Preheat oven to 350°F. Grease a 13 x 9 x 2-inch baking pan.
Combine butter and chocolate in a heat-proof bowl. Set over a pan of barely simmering water and stir until just melted. Remove from heat and cool for 10 minutes.

Beat sugar and eggs until well blended. Whisk in vanilla and salt. Mix in chocolate mixture until thoroughly combined. Gently stir in flour; fold in walnuts, if using. Spread batter into prepared pan and bake for 25 to 30 minutes, or until a toothpick inserted halfway between edge and center comes out clean. Do not overbake; center should be set but not dry. Cool on wire rack before cutting.
Makes 24 bars.