01 -
Heat the oven to 180°C / 350°F. Grease a 20 × 28 cm baking dish with a little of the measured butter.
02 -
Scatter the bread cubes and blueberries in the dish.
03 -
Whisk the eggs, milk, sugar, remaining melted butter, lemon zest, vanilla and salt until combined.
04 -
Pour evenly over the bread. Press the cubes gently into the custard and let them soak for 15 minutes.
05 -
Bake for 35–45 minutes until the centre is set and reaches 71°C / 160°F. The surface should be golden, with no liquid custard pooling when lightly pressed.
06 -
Rest for 15 minutes before serving. Refrigerate leftovers within two hours and use within three days.