Melt the butter in a small saucepan and set aside to cool briefly.
Measure all of the dry ingredients into a large bowl and whisk them together.
Crack the eggs into a separate medium bowl. Add the buttermilk to the eggs and mix well.
Pour the buttermilk mixture into the dry ingredients and mix gently with a rubber spatula until the flour is almost combined. Add the melted butter and mix briefly just until everything is evenly moistened, but still lumpy.
Let the batter rest for about 10 minutes and place a cast iron griddle over medium heat.
When the griddle is hot, melt enough butter to lightly cover it and dollop on the batter. Cook until the the surface begins to develop bubbles and the edges begin to look dry. Flip the pancakes over and cook on the other side until they spring back lightly when pressed gently with a finger.
Serve with more butter and pure maple syrup.