Preheat oven to 350°F (175°C) and grease a 9x13 inch baking pan with non-stick spray.

In a large mixing bowl, combine the cake mix, eggs, 1/2 cup melted butter, and milk; whisk until no large lumps remain.

Pour the batter into the prepared pan and bake for 30 to 35 minutes or until a toothpick inserted in the center comes out clean.

Remove the cake from the oven and immediately use the handle of a wooden spoon to poke holes across the entire surface at 1-inch intervals.

In a medium bowl, whisk together the sweetened condensed milk and caramel sauce until fully combined.

Pour the caramel mixture slowly over the warm cake, ensuring it seeps into the holes; allow the cake to cool completely.

In a small skillet over medium heat, melt 2 tablespoons of butter with the brown sugar and toasted pecans for 2 to 3 minutes until the sugar is dissolved and pecans are glazed; remove from heat and cool.

Spread the whipped topping evenly over the cooled cake.

Sprinkle the glazed pecan mixture over the whipped topping.

Refrigerate the cake for at least 2 hours before slicing and serving.