Cut each apple into 12 segments and put in a large mixing bowl. Add the sugar, sherry and lemon juice and toss to coat well. Add the cinnamon, allspice, ginger and nutmeg and mix well. Set aside to let the flavors blend for 15 minutes.
On a well floured surface, roll the dough out to a 15-inch circle. Transfer to a baking sheet and mound the apples in the center, making sure to leave a generous 2-inch border. Dot the apples with the 2 tablespoons of butter and fold the dough border up around the apples. (It won't meet in the center.) Brush the dough with the heavy cream and sprinkle with the sugar. Place in the bottom third of the oven for 30 minutes. After 30 minutes, transfer to the top third of the oven for an additional 30 minutes. Remove and let cool for 15 minutes before serving.
Put the flour, sugar and salt into the bowl of a food processor. Pulse to combine. Add the butter and pulse until the mixture resembles coarse crumbs. With the processor running add the water 1 tablespoon at a time until a dough just begins to form. Turn out onto a lightly floured surface and pat into a disk. Wrap in plastic wrap and refrigerate for at least 20 minutes.