Preheat oven to 350F
Sift together the flour and cocoa powder. Meanwhile, melt the chocolate in a bowl over boiling water.
In a small pan over medium heat, melt the butter until it just turns golden brown.
Pour the brown butter into the bowl of chocolate, scraping the pan to get the brown bits (this prevents it from overcooking), then add the beer.
Beat together the eggs and sugar until thick and shiny (2 minutes).
Continue beating on low while adding flour mixture and wet ingredients alternatively.
Finish with the vanilla. Do not over mix. Fold in the chips. Pour into a buttered and floured 9 x 13 pan. Bake for 40-45 minutes.