Step 1

Preheat oven to 325°. Spread bread on a rimmed baking sheet and bake, turning bread halfway through, until dried out and lightly golden brown, 20–25 minutes.

Step 2

Meanwhile, butter a 13x9" baking dish. Whisk eggs, cream, milk, brown sugar, cinnamon, cardamom, salt, and orange zest (if using) in a medium bowl.

Step 3

Arrange bread in overlapping rows in prepared dish. Pour custard over, pressing bread down into custard to help soak it up. Let sit 5 minutes, then press down once more. Cover and chill at least 2 hours or up to overnight.

Step 4

Place a rack in top third of oven; preheat to 325°. Let bread sit out at room temperature while oven preheats, at least 30 minutes. Uncover pan, tilt, and ladle custard back over tops of bread. Press down once more to submerge. Brush tops of bread with 3 Tbsp. melted butter. Sprinkle with demerara sugar. Bake bread until it is lightly golden, puffed, and pulling away from edges of pan, and butter is bubbling, 30–40 minutes.

Step 5

Let cool slightly. Serve with crème fraîche and maple syrup alongside.