Mix together the wet ingredients (egg, milk, oil) until well combined.
Add the flour, baking soda, and 1 tablespoon of sugar, and whisk until combined with no large clumps of flour.
Prepare the cinnamon sugar filling by mixing together butter, cinnamon sugar, and 1 tablespoon of the pancake batter.
Heat a tablespoon of butter in a skillet over medium heat.
Scoop a large ladle of the pancake batter onto the skillet and immediately cover with a lid.
Let the pancake cook for about 30 seconds, then swirl the cinnamon sugar mixture on top.
Cover the pan again and let the pancake cook for 4-5 minutes until done.
Repeat with remaining batter, keeping the heat at medium-low to medium to prevent burning.
Serve the pancakes stacked with icing and butter on the side.
