Preheat the oven to 350°F and lightly coat a 9x13-inch rectangular baking dish with non-stick spray or a thin layer of butter.
In a spacious mixing bowl, combine the boxed cake mix, coconut-pecan frosting, eggs, oil, and milk. Use an electric mixer to blend until the batter becomes smooth and homogenous.
Gently fold in the chopped pecans to distribute them evenly through the batter.
Pour the prepared batter into the greased baking pan and spread it evenly.
Transfer the dish to the preheated oven and bake for 30 to 40 minutes, or until a toothpick inserted in the center of the cake emerges clean.
Once baked, take the cake out of the oven. Using the handle of a wooden spoon, poke evenly spaced holes across the entire surface of the cake. Set aside while preparing the sauce.
In a small saucepan placed over medium heat, melt the butter. Add in the sweetened condensed milk, stirring until well combined.
Allow the mixture to reach a gentle simmer, then stir in the chopped pecans. Remove the pan from heat once the sauce is smooth and nutty.
Slowly drizzle the warm praline sauce over the cake, ensuring it seeps into the holes and flows down the sides.
Allow the cake to cool fully at room temperature before slicing and serving.