Whisk eggs and vanilla in a small bowl. In a large bowl, mix together flour, sugar, baking soda, and salt. Add the sour cream (or plain yogurt) and mix just a little bit to barely combine. Add egg mixture and mix just until combined. Don't overmix. In a pan/griddle over med-low heat, add a fraction of the butter if pan/griddle isn't large enough to cook the entire batch in one go. If your pan/griddle is large enough, you can add all the butter for frying at once. Swirl the pan around to get the butter spread evenly. To the pan/griddle, add about ¼ cup of pancake batter for each pancake and wait a couple minutes for bubbles to pop up in the batter before flipping the pancakes. Allow them to cook for about a minute on the second side before moving them to a plate. Continue this process if your pan/griddle required cooking in batches. Top pancakes with butter and maple syrup. Enjoy!