Sift the flour, baking powder, sugar and salt into a mixing bowl. Whisk the eggs with 1 cup milk and add to the dry ingredients. The batter should be quite runny, like pouring cream, so add more milk if you need to.
Let the batter rest in the fridge while you heat ½ tsp oil in a non-stick frying pan on high.
Ladle some batter into the pan and quickly swirl it around to cover the surface. After about 30 seconds bubbles will start to appear on the pancake’s surface and the batter will no longer be runny. Flip the pancake and cook for 30 seconds on the other side.
Slide the cooked pancake onto a plate and sprinkle with cinnamon sugar. Repeat with the rest of the batter, stacking the pancakes and adding some cinnamon sugar to each layer. The sugar will dissolve into a thin, cinnamon-rich syrup. Roll the pancakes when you are ready to eat.