Slice the croissants in half lengthwise. Set aside.
In a medium mixing bowl, combine the cream cheese, zest of one lemon, strained juice of one lemon (about 1 1/2-2 tablespoons), and 3/4 cup powdered sugar. Mix with an electric mixer until light and fluffy.
Spread the lemon cream cheese mixture over the bottoms of the croissants and then replace the tops, pressing down to flatten. Cut into halves (or even fourths if necessary) and arrange the pieces evenly in a 9×13″ pan lightly sprayed with nonstick cooking spray.
Whisk together the milk, eggs, lemon extract, zest from the second lemon, and remaining 1/2 cup of powdered sugar. Pour evenly over the croissants and cover with aluminum foil. Refrigerate for 8-10 hours.
When ready to bake, preheat oven to 350. Bake covered for 30 minutes and then remove the foil and bake for another 20-30 minutes or until the croissants are golden brown and the liquid is absorbed. Remove from the oven and allow it to stand for 5-10 minutes. Cut into squares and top individual servings with Strawberry Sauce, fresh sliced strawberries, and, if desired, sweetened whipped cream. Serves 10-12.