In a small bowl, mix cream cheese, powdered sugar, and vanilla extract until smooth and creamy.
Gently fold in the blueberries, being careful not to crush them too much. Set aside.
Take each slice of brioche or challah and cut a small pocket into the side with a sharp knife, making sure not to cut all the way through.
Spoon 1-2 tablespoons of the blueberry cream cheese filling into each pocket. Don’t overfill, or it will spill out when cooking.
In a shallow dish, whisk together: Eggs, Milk, Granulated sugar, Cinnamon, Vanilla extract, and a Pinch of salt
Heat a large skillet or griddle over medium-low heat and add butter.
Carefully dip each stuffed slice into the custard, letting it soak for about 10 seconds per side.
Lift the bread out and let any excess custard drip off.
Place the soaked bread onto the heated skillet. Cook for 3-4 minutes per side, until golden brown and crisp.
If the bread is browning too quickly before the inside is warm, lower the heat slightly.
Transfer the French toast to plates and top with powdered sugar, fresh blueberries, maple syrup, and whipped cream as desired.
Serve immediately while warm and enjoy every delicious bite!