Homemade Chocolate Brownies

Ingredients

• 4 oz. (113 g) butter or margarine
• 4 oz. (113 g) unsweetened baking chocolate
• 2 tablespoons (30 ml) cocoa
• 4 large eggs at room temperature
• 2 cups (400 g) granulated sugar
• 1 teaspoons (5 ml) pure vanilla extract
• 1 cup (130 g) all purpose flour
• 1 cup (240 ml) chopped walnuts or pecans (optional)
• Nonstick cooking spray