Melt butter and add cake mix. Add 2/3 cup of Evaporated milk. Mix together. Add pecans if desired.
Pat 1/2 of the batter in a 9x13 baking dish for 6 minutes. at 350 degrees.
Unwrap carmels before putting batter in to cook. Melt carmels and 2/3 c. evaporated milk while batter is cooking.
After batter is cooked. Remove from oven and sprinkle chocolate chips over batter. Spread melted carmels over chocolate chips. Drop remaining batter over carmel layer. Cook at 350 degrees for 22-23 minutes. Cool and cut to the size you want. Can be cooled in the fridge to help cool.