Mix the wet ingredients

• Whisk the egg, milk and oil in a bowl until well combined.

Make the pancake batter

• Add the flour, baking soda and sugar.
• Whisk until combined with no large clumps of flour left, without overmixing.

Prepare the cinnamon sugar filling

• Mix the melted butter, brown sugar, cinnamon and a spoonful of the batter.
• Transfer the mixture to a piping bag or a ziplock bag and snip off the corner.

Cook the pancakes

• Heat the butter in a skillet over medium heat until melted and slightly bubbling.
• Scoop a large ladle of batter into the pan and immediately cover with a lid.
• Let cook about 30 seconds, then swirl the cinnamon sugar over the pancake and cover again.
• Cook for 4-5 minutes over medium-low to medium heat until done, without flipping.

Serve

• Stack the pancakes and top with a generous amount of icing.
• Serve with butter on the side.