Grease the baking dish: Rub a 9x13-inch baking dish with butter so the bread doesn't stick to the corners. Set it aside while you prepare the bread and custard.

Cube and dry the bread: Cut the loaf into 1-inch cubes and spread them on a baking sheet for 20 minutes to dry slightly. This helps the cubes soak up custard without turning mushy.

Whisk the custard: In a large bowl, whisk the eggs, milk, heavy cream, brown sugar, cinnamon, nutmeg, vanilla extract, and salt until smooth and pale yellow. Make sure no streaks of egg remain.

Layer the bread: Spread the bread cubes evenly in the prepared baking dish. Try to keep the layer level so the custard soaks through all the pieces.

Pour and press: Pour the custard mixture evenly over the bread cubes. Press down gently with a spatula so every piece is coated and starts absorbing liquid.

Soak in the fridge: Cover the dish with plastic wrap and refrigerate for at least 1 hour, or overnight for a deeper, more custardy texture. This step lets the bread fully absorb the egg mixture.

Preheat the oven: About 30 minutes before baking, preheat the oven to 350°F. Remove the dish from the fridge so it can come closer to room temperature.

Drizzle with butter: Drizzle the melted butter evenly over the top of the soaked bread. This helps the top turn golden and slightly crisp as it bakes.

Bake covered: Cover the dish loosely with foil and bake for 25 minutes. The foil keeps the top from browning too quickly while the inside sets.

Uncover and finish baking: Remove the foil and bake for another 20 to 25 minutes, until the top is golden brown and the center springs back when lightly pressed. A knife inserted in the middle should come out mostly clean.

Rest before slicing: Let the bake rest on the counter for 5 to 10 minutes. This allows the custard to finish setting so the slices hold their shape.

Serve with maple syrup: Slice into squares and serve warm, drizzled with extra maple syrup. Pair with turkey bacon or beef sausage on the side if you want something savory.