In a large bowl, whisk together the eggs, cream, sugar, cinnamon, nutmeg, and vanilla extract.
Preheat the oven to 375°F . Spread the croissants out on a baking sheet and toast for 10 minutes. Arrange half the croissants in the bottom of the baking dish and sprinkle with half the blueberries. Repeat with remaining crosisants and blueberries. Pour the custard over the croissants and let soak for 30 minutes.
Place the dish in a large baking pan. Add enough hot water to come halfway up the sides of the dish. Bake for 50 to 60 minutes, or until the pudding is set and the top is golden. Remove the baking dish from the water and let cool on a wire rack. Serves 6 to 8