Spray a 9 x 13in. baking dish with baking spray.
In a large bowl, whisk together eggs, milk, yogurt, vanilla, brown sugar, nutmeg and cinnamon.
Add in chopped bread and stir together gently.
Pour mixture into baking dish.
Using a spoon, tuck a small dollop of cream cheese in between bread pieces, making sure to use the entire container.
Cover with foil and refrigerate overnight.
Get dish out of fridge and let sit 30 minutes prior to baking.
Preheat the oven to 350 degrees.
Top casserole with small, cut pieces of butter and fresh Blackberries. Sprinkle top of casserole generously with extra sugar and cinnamon if desired.
Bake for 45 minutes or until knife inserted in the center comes out clean. Let sit for a few minutes before serving.