In a mixing bowl pour the melted butter and 1/2 c. milk into the cake mix. Stir. The batter will be sticky. Using a rubber scraper, spread 1/2 the batter into the 9x13 pan. Bake at 350 degrees for 15 minutes.
Remove from the oven and sprinkle the chopped pecans and chocolate chips over the thin cake layer. Melt the caramels with 1/2 c. milk in the microwave.
Pour the caramel evenly over the nuts and chocolate chips. Drop the remaining cake batter (I used my fingers to drop small chunks) on the caramel. Bake 15 minutes more at 350 degrees.