1/2 cup (1 stick) unsalted butter, plus more for the pan 3 ounces finely chopped semisweet chocolate 3 ounces finely chopped unsweetened chocolate 1 cup all-purpose flour 1/8 teaspoon fine salt 3 large eggs 1 1/2 cups sugar 1 teaspoon pure vanilla extract
Cream Cheese Marble: 8 ounces cream cheese, softened (the microwave for 45 seconds at 50 percent power is a great way to do this) 1/2 cup sugar 1 large egg 1 teaspoon pure vanilla extract