Coconut Macaroon Brownies

Ingredients

• 1 cup butter, softened
• 2 cups white sugar
• 4 eggs
• 1 1/2 teaspoons vanilla extract
• 2 cups all-purpose flour
• 3/4 teaspoon cream of tartar
• 1/2 cup unsweetened cocoa powder
• 1/2 cup chopped walnuts
• 4 cups unsweetened flaked coconut
• 1 (14 ounce) can sweetened condensed milk
• 1 tablespoon vanilla extract