Preheat the oven to 425 degrees. Place the butter in a 9-inch skillet or pie plate and transfer the skillet to the oven until the butter is melted. Brush the sides of the skillet with the melted butter.
Add eggs, milk, flour, salt, syrup and vanilla to a blender and process for 1 minute.
Pour batter into the skillet with the melted butter and bake until puffed and set, about 20 minutes.
Serve immediately with desired accompaniments.
Notes
Room temperature ingredients, as well as whole milk and all-purpose flour make the pancake rise the best. But it will still turn out well with whole spelt flour and almond milk.