"Even when strawberry shortcake is crummy it delivers, which is something fast-food franchises and commercial manufacturers have known and banked on forever. They pay people good money to know what people like! Good Humor ice cream bars and KFC parfait cups, even the McDonald’s strawberry sundae -- each flirts with the strawberry-cream construct. But there is a Grand Canyon-esque gap between a perfect strawberry and the strawberry-like flavoring you find in those desserts. Even at the supermarket, those red-skinned, white-fleshed strawberries don’t have much to them. Nothing like the sex bombs you find at your local farmers’ market in the heat of June. It isn’t June right now where I am, and I’ll assume it isn’t where you are either: Use blackberries instead. They are far easier to manipulate into something delicious when they are not at their peak. A bit of sugar and lemon and you can get an inky purple-black mess that will be great. If you have kids, put them to work on this one. For once they can earn their keep. The legacy of this recipe should be mini handprints of seedy blackberry goo on the wall of your kitchen and your pant leg. (Or the sticky shortcake wreckage pictured.)" --Brooks Headley, from Brooks Headley’s Fancy Desserts
In a medium bowl, combine 1/2 cup of the blackberries, the sugar, lemon juice, lemon zest, and salt and mash them together with your hands or your grandmother’s potato masher, until you have a gooey mess. Let the blackberries sit for 30 minutes. (Go make the shortcakes.)
Press the berry mess through a chinois or fine-mesh strainer to get rid of the seeds. Add the remaining 1 1/2 cups blackberries, stir, and serve.
For the shortcakes:
Preheat the oven to 325°F.
In a medium bowl, combine the flour, polenta, salt, baking powder, and granulated sugar. Make a well in the center and pour the cream inside it carefully. Slowly and gently drag the outsides of the well in together until the dough is just combined.
With your hand, divide the dough into 12 irregular blobs and place them on an unlined baking sheet. Brush each lightly with cream, sprinkle with Maldon salt and turbinado sugar, and bake until just set and lightly golden in color, 10 to 15 minutes.
To serve: Split each shortcake in half, stuff with blackberry compote, and douse it with corn cream. Serve to eight-year-olds absolutely immediately.