I often use cake mixes and when making a large cake or using various pan sizes I use the Cake Mix extender recipe. The last time I made a Chocolate Cake addding the extender ingredients into the mix I lost the chocolately goodness of the cake.

Does anyone have any suggestions as to what I should add to the mix to make it the dark chocolate colour and yummy flavour?

I use the extender and add 1/2 cup (or so) of cocoa and sometimes chocolate syrup, works great.

Add a small box of instant chocolate pudding, it's delicious.