Preheat an oven to 180c (350) and grease the pan with room temperature butter or oil spray.
To a 13 by 9 inch baking pan, add the chocolate cake mix, and chocolate instant pudding mix and mix it with a whisk until combined.
In a medium mixing bowl, add the milk and melted butter and mix it with a whisk.
Evenly pour the wet ingredients on top of the dry ingredients in the pan and mix it slightly with a whisk until the dry ingredients are completely covered with the wet ingredients and there are no big clumps of the dry mixture.
Top the batter with lots of chocolate chips and bake the dump cake in a 180c (350f) preheated oven for 35-45 minutes, depending on how gooey you want your cake to be and depending on how hot your oven is.
Allow the dump cake to cool at room temperature for about 10 minutes, scoop it into a bowl or a plate and serve with a large scoop of vanilla ice cream or whipped cream.
Notes
Use room temperature ingredients. It is important that you use room-temperature ingredients like milk. This step ensures that your mixture mixes into a homogenous mixture and bakes perfectly. You don’t want to place cold batter into the oven.
Do not open the oven door in the middle of baking, this can cause the cake from sinking in the middle. If you want to check its doneness, check it 5 minutes before the baking time ends.
Don’t overmix the batter, you don’t want to develop the gluten in the flour. This step ensures you have a moist cake and not a dense and dry cake.
Grease the pan with softened butter or oil spray to prevent the cake from sticking to the pan.
Allow the cake to cool for 10-15 minutes, but serve it warm. Top it with vanilla ice cream or whipped cream. The contrast of the hot chocolate cake with the melty ice cream or whipped cream is irresistible!