Preheat oven to 350°F. Blend first 6 ingredients in blender. Gradually add flour; blend until smooth. Let stand 15 minutes.
Heat medium nonstick skillet over medium-high heat. Brush with butter. Add 2 generous tablespoons batter, tilting pan to coat bottom. Cook until golden on bottom, about 45 seconds. Turn pancake over. Cook until bottom is speckled with brown, about 30 seconds. Turn out onto paper towel. Cover with another paper towel. Repeat with remaining batter, brushing skillet with butter as needed.
Butter ovenproof dish. Sift powdered sugar over speckled side of each pancake, then sprinkle lightly with lemon juice; fold pancakes into quarters. Overlap pancakes in prepared dish. Cover; bake until heated through, about 10 minutes. Serve with more powdered sugar and lemon juice.