Preheat your oven to 350°F (175°C). Gather your materials as it heats up.

Cut the brioche into 1-inch cubes and place them in a large mixing bowl.

In a separate bowl, whisk together the eggs, half and half, vanilla extract, cinnamon, nutmeg, lemon juice, and salt until smooth.

Slice fresh peaches and gently toss them with the brioche cubes to combine evenly.

Carefully fold the custard mixture into the brioche and peaches, ensuring an even coating.

Grease a 9x13 inch baking dish and pour the soaked mixture into it, spreading evenly.

Mix flour, brown sugar, and cinnamon in a bowl, then cut in the chilled butter until it resembles coarse crumbs.

Sprinkle the crumble topping over the brioche and peach mixture evenly.

Bake for 45 to 60 minutes until golden brown and a knife inserted in the center comes out clean.

Let the dish rest for 10 minutes before serving. Dust with powdered sugar.