Preheat the oven to 400℉ with the oven proof pan in the oven. While your oven and pan are heating, begin making the batter.
Combine all the ingredients together and blend for 30 seconds. If using a mixer, use a whisk attachment, or use a blender or food processor. It is very important to add air to the batter so that steam will be created during the baking process. This is what creates the puffed walls you are looking for. Set aside and rest the batter for 15 minutes.
After the rest period, remove the pan from the oven and add the butter. Return the pan to the oven melting the butter to just bubbly.
Remove the pan and swirl the butter to cover the sides of the pan.
Pour the batter into the pan and return to the oven.
Bake for 18-22 minutes, or until the pancake is puffed and golden. DO NOT OPEN THE OVEN DURING BAKING FOR THE FIRST 18 MINUTES!
Serve immediately with toppings of your choice.