Preheat and Prep: Preheat oven to 350°F (175°C). Grease a 9x13-inch baking dish. Cube the bread into roughly 1-inch pieces.
Make Custard: In a large bowl, whisk eggs, milk, heavy cream, granulated sugar, and brown sugar. Stir in melted butter, ginger, cinnamon, nutmeg, salt, whiskey, and vanilla.
Combine Bread and Custard: Place bread cubes in the baking dish. Pour custard over bread and press gently so all pieces soak. Sprinkle chopped crystallized ginger on top. Let sit 15–20 minutes.
Bake: Cover loosely with foil and bake 35 minutes. Remove foil and bake 15–20 more minutes until top is golden and edges caramelized.
Prepare Whiskey Sauce: In a small saucepan, melt butter. Stir in brown sugar. Slowly add heavy cream, then whiskey, vanilla, and a pinch of salt. Cook 3–5 minutes until slightly thickened.
Serve: Serve bread pudding warm with whiskey sauce drizzled on top. Optional: add ice cream or whipped cream.