The best way to get the chocolate in a chocolate stout

i recently brewed the chocolate milk stout recipe from northern brewer. i ordered an extra 4 oz. of cocoa nibs because i like my chocolate stouts to be very chocolatey and i thought the boost in nibs would help. I fermented in primary for a week and transfered to secondary. at the time of transfer i added the 8 oz. of cocoa nibs which i had soaked in vodka for about 3 days. after a week in the secondary i took a sample. there was very little, if any, detectable chocolate flavor. i am very disappointed and am wondering if anybody has any ideas as to what might have gone wrong or what i might be able to do to add some chocolate notes to this beer at this point.

thanks!

I get a nice complex dark chocolate (plus coffee) flavor in my Imperial Stout by using both chocolate malt and pale chocolate malt. I stay away from roasted barley as well, opting to go with carafa and or de-bittered black. The lack of astringency helps the chocolate flavors come through.

I also read somewhere that using cocoa power is better than nibs. I've never used adjuncts in my stouts but get pretty good chocolate with the above method.