To make the crust, combine the flour, sugar, lemon zest, and salt in a food processor and pulse to blend. Add the butter and pulse until the mixture resembles a coarse meal. Add the ice water, 1 tablespoon at a time, and pulse until moist clumps form. Gather the dough into a ball then flatten into a disk. Wrap the dough in plastic and refrigerate until firm, about 1 hour. Preheat the oven to 400 degrees F.
Stir together the berries, lemon juice, sugar and cornstarch in a 10-inch diameter round baking dish. Roll out the crust to a 14-inch diameter circle. Place the crust over the berries in the baking dish. Fold the crust over itself until it fits just inside the baking dish. Cut a 2-inch slit in the center of the dough. Bake until the crust is golden and the berries are bubbly, about 40 minutes.
Meanwhile, whip together the mascarpone, heavy cream, and honey. Cover and reserve in the refrigerator until ready to serve.
To serve, scoop out the crostada into serving dishes and top with the whipped mascarpone.
Recipe courtesy of Giada De Laurentiis