1. Preheat oven to 325 degrees.

2. In a large bowl, lightly whisk together egg yolks, eggs, and salt; set aside.

3. In a large, nonreactive, heavy-bottomed saucepan combine sugar and 1/2 cup water. Place over medium heat and cook, stirring occasionally, until the sugar dissolves and comes to a boil. Increase heat to high and cook, brushing down the sides of the pan with a wet pastry brush but without stirring, until mixture becomes golden amber in color.

4. Meanwhile, place cream in a small, nonreactive, heavy-bottomed saucepan. Place over medium heat and cook until small bubbles appear around the edges of the pan; immediately remove from heat.

5. Remove caramel from heat. When caramel has stopped bubbling, stir in about 1/4 cup of hot cream, taking care as caramel will begin to bubble up once cream is added. Continue adding the cream about 1/2 cup at a time, stirring, adding more cream when bubbles subside, until all cream has been used. Add milk and whisk to combine. Slowly whisk caramel mixture into reserved egg mixture.

6. Place chocolate cake pieces in a 9-by-13-inch baking dish. Pour caramel mixture evenly over cake.

7. Bake until a knife inserted into the center comes out almost completely clean, 30 to 40 minutes. Serve warm.