From the Pastry Dungeon: Concord Grape and Lemon Upside Down Cake

[Photograph: Anna Markow]

As much as I love summer, with its hot sticky days and sweaty nights and more fresh fruit than I can reasonably consume, I have a baker's love for fall. Cooler, drier air makes the scent of warm spices that much more delicious, and the first few dozen apples taste magical. But there's more to fall than apples and cinnamon.

Concord grapes are among every northeastern pastry chef's favorite fruits, but their thick skins and pebble-like seeds keep them relegated to more processed items like sorbets and jams for the most part. It's frustrating to have such a distinct and wonderful flavor trapped in such a limiting form. The best I was able to muster up at one job was a grape jelly Linzer tart, which was pretty and delicious but a rather hard sell.

I couldn't believe my luck recently when I stumbled upon a solution to my grape-loving quandary. I'd heard of a hybrid—the (almost) seedless Thomcord, and they've been popping up at produce stores all over my Brooklyn neighborhood. The fruits are still very much the classically purple grape-flavored orbs, but with thinner skins and easily edible seeds. (The seeds are not much bigger than poppy seeds and with a similarly pleasant crunch and subtle burst of mild bitterness.)They're excellent on their own as a snack, but become as jammy as any other Concords when cooked, so I used them to make a stunning cake.

Though Concords are lovely with spices, I wanted to showcase their perfectly purple flavor with a fairly plain base, and I love the flavor and color combination of grape and lemon. I adapted my favorite basic muffin recipe into a very lemony cake with the addition of the zest of one whole lemon and