Preheat oven to 425F. Melt 2 tbsps of butter in 10-inch cast iron skillet. Put eggs, flour and milk in blender and mix until just blended, 5 to 10 seconds. You can whisk if you don't have a blender but you don't want any lumps in your batter. Pour the batter into skillet and transfer to preheated oven. Bake until top puffs and Dutch Baby is golden, around 25 minutes.

While Dutch Baby is baking, clarify your butter. Melt 3 tbsps of butter in small saucepan over low heat. Skim off any foam from the top. Remove from heat and let rest while solids settler for 5 minutes. Pour through a fine-mesh sieve into a glass measuring cup.

Remove Dutch Baby from oven, drizzle clarified butter over top, sprinkle lemon juice and then dust with powdered sugar using a sifter. Cut into wedges and serve immediately.