In a medium bowl add the rolled oats and milk and leave to soak for 10 minutes until the oats have softened. Meanwhile, melt 1/2 tablespoon unsalted butter in the microwave and put it to one side to cool.
Add the egg, butter and 1/2 tablespoon granulated sugar to the oats, and whisk together to combine. Add the flour and baking powder, pinch of salt, and a pinch of ground cinnamon if desired, and gently whisk together.
Leave to stand for 5 minutes. Meanwhile, heat a medium/large frying pan or skillet over a medium-high height.
Add a small amount of butter to the pan and swirl to coat. Using a spoon add the pancake batter to the pan in 2-tablespoon portions, cooking 2-3 at a time. Cook for around 3 minutes, until bubbles start to appear on the surface and the bottoms are turning golden-brown and flip them over. Cook for a further 2-3 minutes on the other side until also turning golden-brown.
Transfer the pancakes to a warm plate. Repeat cooking the remaining batter, adding a small amount of butter each time. If you're making this recipe for more than one just repeat as necessary.