Preheat oven to 350°F (175°C). Toast croissants on a baking sheet for 7-10 minutes until golden, then cool.
Mix cream cheese and sugar until smooth. Add eggs, then half and half, lemon juice, lemon zest, vanilla, and salt; mix well.
Layer half of croissants and berries in a greased dish, pour half of custard; repeat with remaining croissants and custard. Cover and refrigerate overnight.
Preheat oven to 350°F. Bake covered for 30 minutes, then uncovered for 15 minutes until set. Make lemon glaze while baking and drizzle over.
Serve warm, dust with powdered sugar if desired.
Notes
For best results, prepare the casserole the night before to allow flavors to meld.