Melt the butter and set aside. Combine the eggs, buttermilk, milk, maple syrup, and vanilla in a medium mixing bowl. Add the melted butter and mix. Set aside.
In a small bowl, combine the fresh milled einkorn flour, salt, baking powder, and baking soda. Add to the wet ingredients and mix until just combined and a few small lumps remain. (The batter should be quite thick - slightly more viscous than a muffin batter.) Allow the batter to rest for 2-5 minutes.
Meanwhile, add a few teaspoons of butter to a cast iron skillet and heat on medium-low heat (or heat and prepare an electric griddle). Once the pan is evenly heated, scoop about 1/4 cup of pancake batter into the skillet and slightly spread to about a 4-inch diameter. Allow to cook for about 2 minutes on the first side, and then flip and allow to cook for an additional 1-2 minutes or until just set and lightly golden. Repeat with the remaining batter.
If wanting to keep warm until all the pancakes are cooked, place the pancakes on a cookie sheet in the oven and keep warm at 200 degrees until all the pancakes are ready.
Notes
Buttermilk substitute - If you prefer, you can substitute 1 cup of milk kefir and 1/4 cup of whole milk in place of the buttermilk. This is the way I typically make mine.Allow the batter to rest - Allowing the batter to rest for a few minutes gives gluten a chance to form and results in a fluffier einkorn buttermilk pancake.Only flip once - Avoid flipping the pancakes more than once as this can flatten the fluffiness we want.