I'm typing this post from a laptop keyboard stained with a bit of lemon zest from this very cake--the danger of reading a recipe from the computer while you bake. My go-to concord grape dessert recipe has been pie for the past few years, but having already made one grape pie this summer (a third of which was eaten by our friend's dog, but that's another story)--I wanted to try something different, and may have found a go-to replacement.
This cake is dead simple--the most fussy, but not difficult, part is seeding the grapes that go in the cake. You can find the recipe here, on Serious Eats. Ignore the melted butter at the beginning of the recipe--I think you're supposed to use it to grease the pan, but why bother melting it when you can just swipe a stick around? I made one other small tweak--I didn't have sweet white wine on hand, so used brandy instead. Finally, I recommend checking the cake frequently--after just 23 minutes, mine smelled good and done, and a peek in the oven confirmed that it was golden brown.