This is something I ate for breakfast as a kid. It's as amazing today as it was then. It's best topped with maple syrup or lingonberries. Don't know what those are? Then you're missing out. Google them!
2 c milk (canned coconut milk also works)
2 T butter
1 1/4 c flour
2 t sugar (optional)
1/2 t salt
Beat the eggs. Add the milk and then the dry ingredients.
Heat your oven to 425 and put your baking dish in it with the butter. Melt the butter. Once melted, pour the batter into your dish, over the butter, and return to oven. Bake about 30-40 minutes. The baking time will really be dependent on how deep the batter is. Once the pancake is puffed and golden brown it's done.
It's better to have this in a large dish so that the batter is spread out and not deep. The crispy crust that forms on the top is the best part, and having a larger dish means more crisp. Also, having a smaller dish means a much longer baking time.