In a bowl, mix the cream cheese, dulce de leche, and cinnamon until thoroughly combined. Spread 2 slices of bread with the mixture, half on each slice. Divide the apple slices in half, and arrange the slices on top of the cream cheese topping. Top with remaining bread slices to make 2 sandwiches.
Spray a large non-stick skillet with cooking spray, and place over medium heat. Pan-fry the sandwiches until toasted and golden brown on each side, about 3 minutes per side.