In a medium bowl, combine milk, flour, eggs, and salt. Whisk them together gently until just combined.
Next, prepare your baking dish. Move the oven rack down to the bottom third of the oven, adjusting it lower if you have a smaller oven.
In a 13x9 inch pan (sprayed with cooking spray for easy release), place the butter. Preheat your oven to 450°F (232°C).
Once the oven is preheated, carefully take the pan out. The butter should be bubbling and fragrant. Pour the batter into the hot butter, ensuring it spreads evenly.
Return the pan to the oven and bake for 25 minutes. Watch as the pancakes puff up and turn a beautiful golden brown.
After baking, remove the pan from the oven and allow the pancakes to cool slightly. Slice them into squares or wedges, and serve hot with a drizzle of maple syrup and a sprinkle of powdered sugar.
For the apple variation, take your thinly sliced apples and toss them with sugar, 1/2 teaspoon of cinnamon, and lemon juice in a bowl.
In another bowl, combine the remaining brown sugar and cinnamon. Before pouring the batter into the hot butter, spread a thin layer of the apple mixture over the bottom of the pan.
Pour in the batter over the apples, arranging any remaining apple slices on top. Sprinkle the brown sugar mixture over everything. Return the pan to the oven and bake as usual.
