Step 1: Preheat your oven to 350°F (175°C). Lightly grease a 9×13 inch baking dish.
Step 2: Pour the can of sweetened condensed milk evenly into the bottom of the prepared baking dish. Spread it out gently with a spatula.
Step 3: Sprinkle the dry German chocolate cake mix evenly over the sweetened condensed milk. Do not stir.
Step 4: Distribute the coconut pecan frosting in dollops over the dry cake mix. Use a spoon or spatula to gently spread it out as much as possible without mixing it into the cake mix layer.
Step 5: Evenly sprinkle the chocolate chips and chopped pecans over the top of the coconut pecan frosting layer.
Step 6: Slice the cold butter into thin pats and arrange them evenly over the entire surface of the cake ingredients. Ensure good coverage.
Step 7: Carefully pour the hot water or hot brewed coffee over the top of everything. Do not stir.
Step 8: Bake for 45-55 minutes, or until the top is bubbly and set, and a toothpick inserted into the cake part (avoiding the gooey bottom) comes out mostly clean. The edges should be slightly firm, and the center still a bit soft.
Step 9: Remove from the oven and let cool slightly on a wire rack before serving. This Decadent German Chocolate Dump Cake is best served warm with a scoop of vanilla ice cream or a dollop of whipped cream.