Preheat oven to 350.
Prepare a 10" spring-form pan with non stick cooking spray, set aside.
In large bowl mix together your cake mix, milk, butter and eggs.
Pour half of your mixture in your prepared pan.
Turn your pie face down into pan and cover with remaining cake mix and drop down on counter a few times to make sure the mix covers the whole pie.
Bake in oven for about 60 minutes, checking after 30 minutes and placing tin foil over the top if the edges are getting too done. (Some may need more baking time, this all depends on your oven. Keep checking for doneness with toothpick inserted into center, once it comes out clean it's done).
Remove from oven and let cool for about 10 minutes, then take the sides off of your pan and let cool completely.
Meanwhile to make ganache add your chocolate chips to a bowl.
Heat up your heavy cream slightly until just boiling, in microwave or on stove.
Pour over your chocolate chips and cover for about 5-7 minutes.
Stir you cream into your chocolate, when almost all melted together add your vanilla and continue to stir until smooth.
Set aside to cool slightly, about 15 minutes.
Pour over your cooled cake letting some of the ganache drip down the sides.
Let chocolate set for about another 15 minutes.
Decorate top with pecans if desired.
Cut and serve!