Combine Dry Ingredients: In a large mixing bowl, whisk together the plain flour, baking powder, bicarbonate of soda, salt, and caster sugar (if using). Whisking helps to distribute the leavening agents evenly, ensuring a consistent rise.

Prepare the Wet Ingredients: In a separate, medium-sized bowl, mash the ripe bananas thoroughly with a fork until they are mostly smooth with a few small lumps remaining for texture.

Mix Wet Ingredients: To the mashed bananas, add the buttermilk, lightly beaten egg, melted butter, and vanilla extract. Whisk everything together until just combined.

Combine Wet and Dry: Pour the wet banana mixture into the bowl of dry ingredients. Using a spatula or wooden spoon, gently fold the mixture together until it is just combined. Be careful not to overmix! What works best for me is to stop as soon as there are no large dry streaks of flour left. A lumpy batter is a good batter.

Rest the Batter: Let the pancake batter rest at room temperature for 10-15 minutes. This step is vital for fluffy pancakes as it gives the gluten a chance to relax. You can learn more about the science of why this works over at Serious Eats.

Heat Your Pan: Place a large non-stick frying pan or griddle over a medium-low heat. Add a small knob of butter or a light drizzle of oil and let it melt to coat the surface.

Cook the Pancakes: Ladle about 60ml (a ¼ cup measure works well) of batter per pancake into the hot pan, leaving space between them. Cook for 2-3 minutes on the first side, or until you see bubbles appearing on the surface and the edges look set and golden.

Flip and Finish: Carefully flip the pancakes with a thin spatula and cook for another 1-2 minutes on the other side, until golden brown and cooked through. Transfer the cooked pancakes to a plate and keep them warm in a low oven while you cook the remaining batter, adding a little more butter to the pan for each new batch.