Preheat oven to 420°.
Place 1/3 cup of butter into glass 9 x 13 pan and put pan in preheating oven to melt butter.
Crack 5 eggs into a blender and blend for 1 minute.
Add flour, milk and vanilla and blend for another 30 seconds.
Once butter is melted, remove pan from oven and pour Dutch Baby mixture into pan. Return pan to oven and bake for 20 minutes or until pancake is cooked and fluffy.
Immediately after removing pan from oven, sprinkle pancake with powdered sugar. Serve with your favorite syrup or jam.
