In a medium bowl, whisk together all ingredients except 2 tablespoons butter until evenly combined and moistened thoroughly (some small lumps will remain). Set mixture aside to rest while griddle heats or cover and store in the refrigerator to rest up to 12 hours before using. (If batter rests, stir briefly before using.)
Heat a large seasoned cast iron skillet, frying pan, or griddle over medium heat. To check that the pan's properly heated, sprinkle a few drops of water on pan or griddle and water will "dance" around before evaporating.
Melt 1 tablespoon butter in pan. When it foams, ladle 1/4 cup batter for each pancake and cook until bubbles cover the top, about 3 minutes. Flip and cook until golden brown, another 1 minute. Repeat with remaining batter. Serve immediately with topping of your choice.