Make a well in the dry ingredients and add in ⅔ cup whole milk, 1 large egg, 3 tablespoons salted butter that's been melted, and 2 teaspoons vanilla extract and mix with a whisk or fork just until combined. You want there to be some lumps, but make sure you get all the flour off the bottom of the bowl. Let the batter rest for 10 to 15 minutes before cooking.
Heat a large nonstick skillet or seasoned cast iron over low heat until hot. Drop 1 tablespoon of batter onto the pan to test. If the batter spreads too much and the pancake has a hard time bubbling on the top after a minute or so, increase the heat slightly. You are looking for the batter to have a slow spread thanks to the heat and forming thicker edges that bubble and rise.
Once your heat is set where you want it, cook off the batter, using 1 tablespoon of batter per pancake. Cook until the center bubbles about 1 to 2 minutes and starts to lose its glossy look, then flip with a thin spatula and cook for 30 to 60 more seconds. Transfer to a plate and cook off the rest of the batter. Serve with butter and syrup.
Store leftover Silver Dollar Pancakes in an airtight container or Ziploc bag in the refrigerator. Enjoy the leftovers for up to 4 days.