You will probably find more cakes than brownies, but most coffeeshops will have some "edibles" on their menu. You should check out
FBN's Coffeeshop Menus site and explore your options.
From my experience, the potency of the cakes at the various coffeeshops varies considerably. I've had my "socks blown off" by some Paradox and Utopia come to mind, while at others the effects have been minimal at best, Biba. You might try some of the mid-range cakes (HGF, Tweede Kamer, Dampkring) the latter two (2) coffeeshops wrap theirs in foil guaranteeing moistness.
If you are a cake "newbie," the key will be to go slowly by taking a quarter of a cake or less, eating it, then waiting for one (1) hour to see what the effects have been. I would strongly recommend that the cake "initiation, if it is that, not take place on an alcohol base.
Talking to the budtender is always a good idea. In the conversation, make sure you ask what went into the cakes and how much. Is it 1gram, .4 grams, or something else? Was it an Indica or a Sativa?