Brookies

Name: Brookies
Prep time: 15 min
Cook time: 35 min
Total time: 1 h
Yield: 16
Ingredients: Ingredients; 1/2 cup unsalted butter, melted; 1/2 cup granulated sugar; 1/2 cup packed brown sugar; 2 large eggs; 1 teaspoon vanilla extract; 1 cup all-purpose flour; 1/3 cup unsweetened cocoa powder; 1/2 teaspoon baking powder; 1/2 teaspoon salt; 1/2 cup chocolate chips; 1/2 cup semi-sweet chocolate chunks; 1/4 cup chopped walnuts (optional); Cookie Layer; 1/4 cup softened butter; 1/4 cup brown sugar; 1 egg yolk; 1/2 cup all-purpose flour; 1/4 teaspoon salt; 1/3 cup chocolate chips