Unbelievable Blueberry French Toast Casserole

Bahan-bahan (12 porsi)

• 1 (12–14-ounce/340–400g) loaf of sturdy day-old bread, such as French bread, sourdough, brioche, or challah, cut in 1-inch cubes*
• 1 cup (140g) fresh or frozen blueberries
• 2 cups (480g/ml) whole milk
• 8 large eggs
• 1/2 cup (120g/ml) heavy cream
• 1/2 cup (100g) packed light brown sugar
• 2 teaspoons pure vanilla extract
• 2 teaspoons ground cinnamon
• 1 teaspoon fresh lemon zest
• pinch of salt
• 1/3 cup (67g) packed light or dark brown sugar
• 1/3 cup (42g) all-purpose flour (spooned & leveled)
• 1/2 teaspoon ground cinnamon
• 6 Tablespoons (85g) unsalted butter, cold and cubed
• optional: extra blueberries, maple syrup, and/or confectioners’ sugar for topping