To make the cake preheat the oven to 350 degrees. Spray a 9 x 13 baking dish with cooking spray and set aside.
In a large bowl combine the melted butter, one cup of milk, and three eggs. Mix until well combined.
Add in the cake mix and mix for one minute.
Pour the batter into the prepared cake pan. Bake for 30 minutes or until a toothpick inserted into the center comes out clean.
Allow the cake to cool for 10 minutes then using the handle of a wooden spoon or a skewer poke holes all over the cake.
In a medium mixing bowl combine the lemon pudding mix and remaining milk. Mix well to combine. Pour half the pudding over top of the cake and smooth over top of the holes making sure the pudding goes down into it. Add more pudding until no more will go down into the holes of the cake.
Allow the cake to cool completely.
To make the frosting mix together the Cool Whip, powdered sugar, and lemon extract. Whip until smooth. Spread over top of the cake.