Fudge Brownies with Chocolate Cream Cheese Frosting

Ingredients

• 3/4 cup natural unsweetened cocoa powder, sifted
• 1/4 teaspoon salt
• 1 teaspoon vanilla extract
• 10 tablespoons unsalted butter, 1 stick plus 2 extra tablespoons
• 1/2 cup all-purpose flour
• 3/4 cup granulated sugar
• 1 large egg yolk, room temperature
• 1 to 1 1/2 cups confectioner's sugar, sifted
• 1/3 cup brick-style cream cheese, softened to room temperature
• 1/2 cup light brown sugar, lightly packed
• 2 large eggs, room temperature
• 1 tablespoon corn syrup
• 1/3 cup unsalted butter, softened to room temperature
• 1/4 to 1/3 cup natural unsweetened cocoa powder