Butter 2 cake pans. Line pans with parchment paper.
Heat 1/2 cup butter, brown sugar and sweet condensed milk. Heat until sugar is melted but DO NOT BOIL Pour into pans. Sprinkle with chopped pecans. Set pans aside.
2Add flour, cocoa, baking soda ,salt and sugar to a large bowl. Mix well. Add beaten eggs, sour cream, oil, vanilla and vinegar and 1 cup HOT water.
Mix well with wooden spoon. Do not beat with mixer.
Pour over pecans in pans.
Bake 35 - 40 mins. Cool in pans about 10 mins.
Then remove from pans. Remove parchment paper. Cool completely
3Drizzle fudge topping over sugar topped cake. Drizzle melted chocolate chips over that. Then place the other layer on top..Repeat with drizzled fudge topping and then drizzled with melted chocolate chips. Then frost the sides only with your favorite chocolate frosting.