To make syrup, segment oranges: Cut 1/4 inch off the top and bottom so fruit will sit flat on a cutting board. Trim skin and pith, slicing in a downward motion. With fruit in your hand, use a paring knife to carefully cut between segments and white membrane that holds orange together. Place segments in a small bowl and squeeze remaining membrane over bowl to extract any juice, then discard. Add maple syrup and toss to coat, then set aside.
To make pancake batter, whisk together flour, baking powder, and salt in a medium bowl. In a large bowl, whisk egg, then stir in Greek yogurt, soy (or almond) milk, vegetable oil, maple syrup, and vanilla extract. Fold flour mixture into yogurt mixture until just combined and set aside.
In another deep bowl, whisk egg white vigorously, using a balloon whisk, until white and foamy and the tips hold soft peaks. Gently fold into batter until just incorporated; don’t overmix.
Lightly coat a large skillet with cooking spray and heat over medium-low. Spoon batter into the pan, about 2 tablespoons per pancake, and spread into 3-inch rounds. Cook for 2 minutes or until pancakes have browned on the bottom and you see a few bubbles in batter. Flip and cook for 1 to 2 minutes more. Repeat with remaining batter to make 12 pancakes.
Divide pancakes among four plates and top with prepared maple syrup, making sure to evenly distribute the orange segments. If desired, top each with 1 tablespoon sliced almonds and garnish with mint leaves. Serve immediately.