Hey nickispider,
I totally feel you on your frustration with cakey vegan brownies. Authentic brownies are really hard to replicate because of the way that the butter and eggs work in them. It's effing magic in brownies for some reason- it's real hard to get that fudgey density in vegan brownies.
I've spent several years developing
Chocolate Dream Brownies and
Choc-tacular Brownies, (both linked) which are extremely dense and fudgy.
How many Tablespoons of flax seeds were in your previous brownie recipe? You should be able to get away with up to 3 Tablespoons of golden flax meal in an 8 x 8 inch square baking dish before the flax starts interfering with the flavor.
Good luck, and if you find a recipe that you're into, please share!
Mattie