Preheat the oven to 425F.
In a large bowl, whisk the eggs well. Add in the sourdough discard, milk, maple syrup, salt, and vanilla. Whisk well to combine, or use a hand mixer on medium speed until completely smooth.
Add the Salted butter to a 9X13 glass baking dish and place it in the oven.
Once the butter has melted, pull the baking dish out of the oven.
Swirl the butter around the baking dish and pour in the sourdough batter.
Sprinkle the surface evenly with the wild blueberries, then the cubed cream cheese.
Bake in the preheated oven for 20-22 minutes.
Remove from the oven and serve with maple syrup.