Preheat oven to 400 degrees. Grease a standard 15-by-18 rimmed baking sheet with oil. Line the pan with parchment paper for easier removal.
In a large bowl, mix eggs, applesauce, oil, maple syrup, vanilla, and milk.
In a medium-sized bowl, whisk flour, baking powder, cinnamon, and salt.
Dumb flour mixture into the wet ingredients and stir until just combined and no dry flour remains. Pour batter onto your prepared baking sheet and spread into an even layer.
Decorate the top of the pancake batter as desired. Bake until golden brown around the edges and a toothpick inserted into the center of the baked pancake comes out clean, 10 to 12 minutes. Allow to cool for 5 to 10 minutes, dust with powdered sugar, if using, then slice into squares. Serve with maple syrup, if desired.