Preheat oven to 425°.
Combine sliced pears, brown sugar, and lemon juice. Heat a 10-inch cast-iron or heavy ovenproof skillet over medium heat. Add pear mixture; sauté 5 minutes or until pears are golden. Remove pear mixture from pan, and keep warm.
Lightly spoon the flour into a dry measuring cup, and level with a knife. Place the flour in a large bowl. Combine the milk, granulated sugar, salt, and eggs, stirring the mixture well with a whisk. Add the milk mixture to the flour, stirring with a whisk until well-blended.
Melt the butter in pan. Pour batter into pan. Bake at 425° for 25 minutes or until puffy and golden. Spoon the pear mixture into center of pancake; sprinkle with powdered sugar. Cut into 6 wedges. Serve immediately.