- 1/2 cup (67 grams) all-purpose flour
- 1/2 teaspoon granulated sugar
- 1/2 teaspoon kosher salt (skip if you used salted butter above)
- 2 1/2 tablespoons unsalted butter cut into small cubes
- 2 tablespoons cold buttermilk (plus a splash more if your dough feels dry)
- 1/2 cup blueberries and raspberries
- 1 tablespoon granulated sugar
- 1 teaspoon cornstarch
- A pinch of kosher salt
- A squeeze of lemon (and lemon zest if you want)
- Turbinado sugar before baking, optional
- Vanilla ice cream or whipped cream for serving
- Place a rack in the upper third of the oven and preheat oven to 400 degrees F. Line a small baking pan with parchment paper and set aside.
- In a small bowl, whisk together flour, sugar, and salt. Add the cold butter and use your fingers to break the butter up into smaller bits, the size of small peas and oat flakes. Create a well in the center of the dry ingredients and add buttermilk. Use a fork to bring it all together into a shaggy dough.
- Turn the shaggy dough out onto the counter and bring together into a small disk. Add a splash more buttermilk if the dough feels dry. Wrap in a piece of plastic wrap or waxed paper and refrigerate for 15-20 minutes.
- In a small bowl toss together berries, sugar, cornstarch, salt and a little squeeze of lemon.
- Lightly flour the counter and roll the crust into a 6 or 8-inch circle just thicker than 1/4-inch. Spoon fruit onto the crust and fold the crust up over the fruit. Brush the edges with buttermilk and sprinkle with turbinado sugar.
- Use a large spatula or bench scraper to transfer the crostata to the prepared baking pan. Bake for 22-24 minutes until golden and bubbling. Serve warm with a dollop of whipped cream or ice cream.