Preheat oven to 350°F (175°C). Lightly butter a 9x13-inch baking dish. What it should look like: A clean, lightly greased rectangular baking dish ready to hold the bread.

Cut 1 pound of day-old bread into 1-inch cubes. Arrange cubes evenly in the prepared dish, filling it about three-quarters full. What it should look like: Bread cubes loosely packed, not compressed, with visible gaps between pieces.

In a large mixing bowl, crack 6 eggs and whisk vigorously for 1–2 minutes until well blended and slightly frothy. Checkpoint: Eggs should be uniform in color with no visible whites.

Add 1.5 cups whole milk, 0.5 cup heavy cream, 3 tablespoons granulated sugar, 2 tablespoons brown sugar, 2 teaspoons vanilla extract, 1 teaspoon ground cinnamon, 0.25 teaspoon ground nutmeg, and 0.125 teaspoon salt to the eggs. Whisk continuously for 2–3 minutes until all sugar dissolves and custard is smooth. What it should look like: A uniform, pale custard with no visible sugar crystals. It should feel creamy when you run it through a whisk.

Pour the custard mixture slowly and evenly over the bread cubes, 2–3 minutes. Use a spatula to gently stir, ensuring every piece of bread gets coated. Some cubes will float; this is normal. Checkpoint: Bread should feel soft when pressed but still maintain its shape.

Let the assembled dish sit at room temperature for 10 minutes so the bread can absorb more custard. Then press down gently with the back of a spatula to compress slightly. What it should look like: Bread will have sunk slightly and the custard will partially cover the top layer.

Cover the baking dish with aluminum foil and refrigerate for at least 2 hours, or up to overnight. This step allows deep custard absorption. Tip: Overnight assembly gives the best texture—custardy and tender throughout.

When ready to bake, remove the dish from refrigerator 15 minutes before baking. Preheat oven to 350°F (175°C). Drizzle 4 tablespoons melted unsalted butter evenly over the bread mixture. Stir gently but thoroughly so the butter distributes. What it should feel like: Bread cubes should glisten with butter but not be swimming in it.

In a separate medium bowl, combine 4 medium fresh peaches (peeled, pitted, and sliced into 0.5-inch wedges), 2 tablespoons brown sugar, 3 tablespoons honey, 1 tablespoon fresh lemon juice, and 0.5 teaspoon vanilla extract. Toss gently for 1 minute until peaches are evenly coated. What it should look like: Peaches should glisten with the honey-sugar mixture and smell fragrant.

Scatter the peach slices and all accumulated juices evenly over the top of the bread mixture, using a spoon to distribute the syrupy liquid. What it should look like: Peaches should be spread across the top in a single mostly even layer, with liquid pooled between pieces.

Cover the dish with foil (shiny side facing down) and bake for 25 minutes at 350°F (175°C). What it should smell like: Warm, custard-y, with hints of cinnamon and peach.

Remove foil carefully (watch for steam) and bake uncovered for an additional 20–25 minutes until the top is golden brown and the edges are slightly puffed. What it should look like: The bread should be visibly browned around the edges and on top, and the peaches should be caramelized with some darkened edges. The center should jiggle just slightly when the dish is gently shaken.

Insert a knife or cake tester into the center of the dish. It should come out clean or with just 1–2 moist crumbs clinging to it. What it should feel like: The top should be firm to the touch but slightly springy, not hard. The interior should feel custardy when you insert the knife.

Remove from oven and let rest on the counter for 10 minutes. Why: This allows the custard to set slightly and makes serving easier. The dish will continue to cook gently from residual heat.

Dust the entire top generously with confectioners sugar using a fine-mesh sieve, 1–2 minutes. What it should look like: A light, snowy white coating across the top, with some sugar settling into the crevices between peaches and bread.

Serve warm directly from the dish using a large spoon or spatula. Transfer portions to plates and top each serving with a dollop of fresh whipped cream and a small drizzle of maple syrup. What it should taste like: Creamy, custardy bread with caramelized peach notes, warm spice, and a subtle sweetness balanced by lemon brightness.