Preheat an electric griddle to 375ºF or a nonstick frying pan over medium-low heat.
Whisk together ¼ cup melted butter and the eggs. Whisk in the water, buttermilk, and vanilla extract.
Add the flour, sugar, baking powder, and salt, then whisk until the flour is incorporated. Set aside for 5 minutes.
Meanwhile, melt the second ¼ cup of butter and have it ready near your griddle or frying pan. Stir together sugar and cinnamon and place in a flat-bottomed container.
Pour 1 teaspoon of butter in a little pool on the cooking surface. Place about ⅓ cup of batter on the pool of butter.
Cook the first side for about 5-6 minutes, then flip and cook about 2-3 minutes on the second side. You want the pancake to be fairly firm before flipping or it will spill over.
Once the pancake is cooked, transfer it to the container of cinnamon sugar. Using a spoon, cover the pancake in cinnamon sugar. Flip the pancake over and spoon more cinnamon sugar on the other side. Light dust off and transfer to a serving plate. Serve immediately.