Step 1

Combine water and butter in a 4-quart heavy saucepan and bring it to a simmer. Once the butter has completely melted, add the flour and stir will, then continue to stir over medium heat for 2 minutes. It is important to cook it the entire 2 minutes so that the flour will cook completely. The dough will stick to the sides of the pan and then form a ball keep stirring and cooking.

Step 2

After 2 minutes, remove from the heat and place dough in bowl of an electric mixer. Allow to cool about 5 minutes. Then, with the machine running on low, add the salt and eggs one at a time with time in between each addition. The dough will change in appearance from looking like scrambled eggs to a shiny batter. Continue to beat for about 2 minutes until it pulls away from the bottom or sides of the bowl.

Step 3

Spread the dough into a greased 9 x 13-inch baking dish, pushing it into the corners and up to the sides.

Step 4

Preheat oven to 425 degrees F and bake for 15-18 minutes. It should no longer look wet and should look lightly golden brown.

Step 5

Return the pan to the oven with the heat off, leave the door ajar and allow to cool to room temperature.

Step 6

Make the pudding according to package directions and chill. May be used immediately or chilled, covered up to one day before assembling cake. Thaw whipped topping in the refrigerator for 4 hours before assembling cake.

Step 7

After the base has cooled completely, spoon prepared pudding into the center, smoothing evenly and pushing to the edges. Top with the whipped topping, again smoothing evenly and swirling in a decorative pattern. Drizzle with about 1/3 cup of the chocolate sauce. Cover cake lightly with plastic wrap and chill for 1 hour before serving.

Step 8

In a 1-quart saucepan over medium high heat, combine milk, butter, and salt and bring it to a boil. Combine the sugar and cocoa powder and stir to get rid of any lumps, then add to the pan and continue to stir with a whisk until it boils and is thickened, at least 2 minutes.

Step 9

The mixture should coat the back of a spoon when thickened. It will continue to thicken as it cools.

Step 10

Remove chocolate sauce to a small bowl and cover and chill 1 hour before using. Sauce can be stored in the refrigerator up to a week. Bring to room temperature and stir before using.