Toss bread and blueberries in the prepared pan. Whisk eggs in a large bowl. Add milk, butter, brown sugar, ginger, vanilla and salt; whisk to combine. Pour the custard over the bread mixture. Sprinkle with almonds. Coat a piece of foil with cooking spray and cover the pan, coated-side down. Place another 9-by-13-inch baking dish on top as a weight. Refrigerate for at least 8 hours or up to 1 day.