In a mixing bowl, combine the all-purpose flour, granulated sugar, baking powder, and salt. Whisk them together until well mixed.
In a separate small bowl, whisk together the milk, egg yolk, vegetable oil, and vanilla extract until fully combined.
Pour the wet mixture into the bowl with the dry ingredients. Stir gently until just combined. Be careful not to overmix; it's okay if there are a few lumps.
Place a non-stick skillet over medium heat and add a small amount of butter to coat the pan.
Once the skillet is hot, pour the batter into the pan, using about half of it for one pancake. Cook until bubbles form on the surface and the edges look set, about 2-3 minutes.
Carefully flip the pancake using a spatula and cook for another 1-2 minutes until golden brown. Repeat with any remaining batter.
Serve your pancakes warm, topped with syrup, fresh fruit, or any toppings you like.