In a large mixing bowl, combine the flour, sugar, baking powder, baking soda, and salt. Whisk thoroughly to ensure the leavening agents are evenly distributed throughout the flour.
In a separate medium bowl, whisk sour cream, milk, eggs, and vanilla until smooth. Slowly stream in the melted butter while whisking constantly.
Create a well in the dry ingredients. Pour in the wet mixture and fold gently with a spatula just until combined. Note: Leave small lumps; do not over-mix.
Let the batter sit for 10 minutes
Heat a non-stick griddle or heavy-bottomed skillet over medium-low heat. Lightly grease with butter or oil.
Pour ¼ cup of batter per pancake. Cook until bubbles form on the surface and edges look set. Flip and cook for 1–2 minutes more until golden brown.