Preheat Oven:
Preheat oven to 350°F (175°C). Grease a 9x13-inch baking dish.
Prepare Bread:
Cube the bread into roughly 1-inch pieces and place in the prepared baking dish. Sprinkle raisins or nuts if using.
Make Custard:
In a medium bowl, whisk together eggs, milk, cream, granulated sugar, brown sugar, vanilla, cinnamon, nutmeg, and salt until fully combined.
Combine:
Pour the custard evenly over the bread cubes, pressing lightly to ensure all bread absorbs the liquid. Let sit for 10–15 minutes to soak.
Bake:
Cover with foil and bake for 30 minutes. Remove foil and bake an additional 20–25 minutes, or until the top is golden brown and a knife inserted comes out clean.
Make Sauce (Optional):
In a small saucepan over medium heat, combine sugar, butter, and heavy cream. Stir until smooth and simmer for 3–4 minutes. Remove from heat and stir in vanilla. Serve warm over the bread pudding.