Preheat your oven to 350°F (or 325°F if using a dark or nonstick pan) and thoroughly grease a 9×13-inch metal baking pan with non-stick cooking spray or butter. In a large mixing bowl, combine the chocolate cake mix, eggs, vegetable oil, and water, whisking vigorously for 2 full minutes until a smooth, completely aerated batter forms.

Pour exactly half of the prepared cake batter into the bottom of your greased pan, using an offset spatula to smooth it evenly into the corners, and bake for 12 to 15 minutes just until the surface tension sets and a thin skin forms over the top layer.

While the first half of the cake bakes, combine the caramel bits, evaporated milk, and melted unsalted butter in a medium, heavy-bottomed saucepan over low heat. Cook slowly while stirring continuously for 5 to 6 minutes until the caramels completely break down and emulsify with the milk lipids into a smooth, thick, and uniform liquid lava.

Remove the par-baked cake from the oven and immediately pour the hot caramel mixture uniformly across the set chocolate surface, leaving a small quarter-inch border along the perimeter edges of the pan.

Scatter 1 cup of the toasted chopped pecans and the entire cup of chocolate chips evenly over the hot caramel layer.

Carefully ladle the remaining raw cake batter directly over the chocolate chip and pecan layers, working slowly from the edges inward to completely insulate and seal the hot filling beneath the smooth chocolate top sheet.

Sprinkle the remaining 1 cup of chopped pecans evenly across the raw top batter layer.

Return the pan to the oven and bake at 350°F for an additional 25 to 28 minutes. Watch the center closely and remove from heat the moment the top cake layer springs back gently when touched and a toothpick inserted into the cake portion comes out clean. Let the cake cool completely in the pan for at least 30 minutes to allow the molten internal sugars to firm up into a fudgy, sliceable state before serving.