Combine the flour, yeast, salt, honey, oil, wine, egg, water, and orange zest in the bowl of a standing mixer fitted with a dough hook. Give the mixture a few turns with a rubber spatula until a rough dough forms. Knead on medium-high speed until smooth and silky, 6 to 8 minutes.
Transfer the dough to a lightly oiled bowl or dough-rising container, cover the bowl with plastic wrap, and let stand at room temperature for up to 1-1⁄2 hours.
Oil the bottom and sides of a rimmed baking sheet. Turn the dough onto a lightly floured countertop and divide into 2 equal pieces. With a floured rolling pin, roll 1 of the pieces into a rectangle measuring about 15 by 12 inches. Place the rectangle on the prepared baking sheet and press the dough so that it covers the bottom and comes up the sides of the sheet.
Sprinkle three-quarters of the grapes evenly over the dough. Roll out the remaining piece of dough and place it on top of the grapes, stretching it to cover. Sprinkle the remaining grapes evenly over the dough. Allow the schiacciata to sit, uncovered, for 20 minutes.
Preheat the oven to 400°F. Bake the schiacciata in the middle of the oven until well-browned, 45 to 50 minutes. Let cool on the baking sheet for 10 minutes, and then lift it with a large spatula onto a wire rack to cool completely before cutting into squares. Grape Schiacciata will keep at room temperature in an airtight container for up to 2 days.
For a rosemary-walnut schiacciata, replace the orange zest with 3.75 ounces/ 15 grams (2 tablespoons) of fresh rosemary and the grapes with 7 ounces/200 grams (1-3⁄4 cups) of walnuts, chopped.
For a cherry tomato–anise schiacciata, replace the orange zest with 3.75 ounces/15 grams (2 tablespoons) of anise seeds and the grapes with 18 ounces/500 grams (3-1⁄2 cups) of cherry tomatoes.