In a blender, pulse rolled oats until they reach a flour-like consistency.
In a large bowl, whisk together the ground oats, protein powder, baking powder, salt, and cinnamon.
In a separate bowl, beat the eggs, then add almond milk, Greek yogurt, vanilla extract, and honey or maple syrup. Whisk until well combined.
Pour the wet ingredients into the dry ingredients and stir until just combined. Don't overmix; a few small lumps are fine. Let the batter rest for 5 minutes to thicken.
Heat a non-stick pan or griddle over medium heat. Lightly coat with cooking spray or butter.
For each pancake, pour about ¼ cup of batter onto the hot surface. Cook until bubbles form on the surface and the edges look set (about 2-3 minutes).
Flip and cook for another 1-2 minutes until golden brown.
Transfer to a plate and repeat with remaining batter.