In a large bowl, add the strawberries, 3 tablespoons of the granulated sugar, and the lemon juice and stir until it is well combined and the berries are evenly coated.
Cover the bowl and refrigerate the strawberry mixture for at least 30 minutes and up to overnight.
Arrange a rack in the middle of the oven.
Preheat the oven to 350 degrees F.
Coat a 9x13-inch baking dish with cooking spray.
Evenly spread the bread cubes in a single layer on a rimmed baking sheet and bake until they are dry and very lightly golden-brown, about 10 minutes.
Set the bread cubes aside to cool slightly.
Evenly spread 1/2 of the toasted bread cubes in an even layer in the prepared baking dish.
Evenly arrange the cream cheese cubes over the bread layer.
Using a small spoon, evenly dollop 1/2 of the strawberry jam over the cream cheese.
Evenly arrange the remaining toasted bread cubes on top of the jam.
In a large bowl, add the eggs, the half-and-half, the remaining granulated sugar, the vanilla, and the salt and whisk until it is fully combined.
Evenly pour the egg mixture over the bread and then gently press down on the top with your hands to ensure the bread gets saturated.
Evenly dollop the remaining jam over the top of the casserole.
Cover the baking dish and refrigerate for at least 1 hour and up to overnight.
Arrange a rack in the middle of the oven.
Preheat the oven to 350 degrees F.
Allow the casserole to sit at room temperature while the oven preheats.
Uncover the casserole and bake until it is set, puffed, and the top is golden-brown, about 40-45 minutes.
Allow the casserole to cool for 5 minutes.
Right before serving, stir the macerated strawberries and evenly spoon them over the top of the casserole.
Dust the casserole with the powdered sugar.
Serve.