In a shallow dish, whisk together the 5 eggs, heavy cream, whole milk, vanilla extract, and sugar until smooth and well combined.

Heat a large skillet or griddle over medium heat and lightly grease with butter or cooking spray.

Dip each slice of sourdough bread into the custard mixture, letting it soak for 10-15 seconds per side to fully absorb the flavors without becoming overly saturated.

Place the soaked slices onto the preheated skillet and cook for 2-3 minutes per side, or until golden brown and slightly crisp around the edges.

Transfer the French toast to serving plates. Dust with powdered sugar, add a dollop of whipped cream, and drizzle with blueberry syrup or compote, if desired. Serve immediately.