01 -
Grease a 9x13-inch baking dish. Evenly arrange sourdough cubes in the dish, then scatter blueberries and lemon zest over the bread.
02 -
Whisk together eggs, whole milk, heavy cream, granulated sugar, vanilla extract, salt, and lemon juice in a large bowl until smooth and fully combined.
03 -
Pour the custard evenly over the bread and berries, pressing down lightly to ensure the bread absorbs the mixture thoroughly.
04 -
Cover the dish and refrigerate for at least 30 minutes or overnight for optimal flavor and texture.
05 -
Set oven temperature to 350°F in preparation for baking.
06 -
Drizzle melted butter over the custard surface. Combine granulated sugar and cinnamon and sprinkle evenly on top.
07 -
Bake uncovered for 45 minutes, until the center is set and the top is golden brown.
08 -
Allow to cool for 10 minutes before serving warm. Optionally accompany with maple syrup or powdered sugar.