Step 1: Preheat your oven to 350°F (175°C). Cut brioche or challah into 1-inch cubes and place in a greased 9x13 inch baking dish.
Step 2: In a mixing bowl, beat softened cream cheese with 1/4 cup of granulated sugar until smooth and creamy.
Step 3: Gently fold in blueberries into the cream cheese mixture.
Step 4: In another bowl, whisk together the remaining sugar, eggs, half and half, vanilla extract, lemon juice, lemon zest, and salt until well combined.
Step 5: Pour the custard mixture over the bread cubes, then dollop the cream cheese and blueberry mixture over the top. Press down gently.
Step 6: Cover with foil and bake for 30 minutes, then remove foil and bake for an additional 15-20 minutes until golden.
Step 7: Let cool for a few minutes, then serve warm with your choice of sauces.