There is a recipe online for blueberry brownies, but I think it called for blueberry preserves. When my blueberries produce this year, I am just going to throw a handful in the brownie mix.
By the way, for the chocolate afficiandos...the absolute, hands down, very BEST chocolate I have ever put in my mouth was at a place in San Francisco called Citizen Cake. The chef/owner makes these miniature cakes. One is called After Midnight. My last trip to SF, I got off the plane, got my car, and went straight there as fast as I could. I'm just afraid they are going to call the police someday thinking I'm some sort of a pervert over the moaning noises I make while eating it lol