Makes 40 small pieces

3 cups semisweet baking chocolate

1 14-ounce can sweetened condensed milk

2 tablespoons unsweetened cocoa powder

2 tablespoons butter

1½ teaspoons vanilla extract

½ teaspoon salt

1 cup walnuts, chopped (optional)

1. Line an 8 x 8-inch square pan with foil.
2. In a large saucepan, melt together chocolate, sweetened condensed milk, cocoa powder, and butter over medium heat until mixture is completely smooth.
3. Stir in vanilla extract, salt, and chopped nuts (if using).
4. Pour mixture into pan, smoothing to an even layer.
5. Chill in refrigerator for 4 hours, or until firm.
6. Remove foil from pan and cut fudge into squares.