Preheat oven to 375 degrees. Scatter bread on a rimmed baking sheet and bake until dry and light golden brown, about 12 minutes, tossing halfway through. Crush half the bread to make crumbs. In a large bowl, combine butter, 1/4 cup sugar, and 3 tablespoons cider, then stir in bread pieces and crumbs.
Combine apples, dates, flour, lemon juice, salt, allspice, and remaining 1/2 cup sugar and 3 tablespoons cider. Stir in 1/2 cup bread mixture. Transfer to an 8-inch square baking dish and top with remaining bread mixture. Cover with foil and bake until bubbling in center, 40 to 55 minutes. Uncover and bake until top is golden, 5 minutes more. Let cool 15 minutes (or let sit at room temperature, up to 8 hours). To serve, divide among bowls and top with cream.