Mix softened cream cheese, powdered sugar (optional), and vanilla extract until smooth. Spread the mixture on one side of each bread slice. Top half of the slices with strawberry jam, then press another slice of bread on top to form sandwiches.
Whisk together the egg and milk in a shallow bowl. Spread panko breadcrumbs on a plate or in another shallow bowl.
Dip each sandwich into the egg mixture, coating both sides. Let excess drip off, then press into the breadcrumbs, ensuring an even coat.
Heat 1/2 inch of vegetable oil in a skillet over medium heat (about 350°F/175°C). Fry the sandwiches for 2-3 minutes per side until golden and crispy. Transfer to a paper towel-lined plate to drain.
Dust with powdered sugar, garnish with fresh strawberries and whipped cream, and drizzle with maple syrup or honey if desired.