I love this pancake! Good apples to use would be Granny Smith, Jonagold or McIntosh. If you have access to heirloom apples, choose some that have some tartness to them. This recipe is adapted from "The Pancake Handbook".
Combine apples, sugar, 2 T of the lemon juice and cinnamon in a medium bowl; toss to coat apples.
Melt 2 T of the butter in a skillet over medium-high heat; add apples, cook just until soft, 3 minutes; remove from heat and set aside.
Heat oven to 450 degrees.
Whisk together eggs and milk in a bowl until well blended, whisk in flour and salt to form a slightly lumpy batter.
Melt remaining 4 T of the butter in an oven-proof 10-inch skillet (a well-seasoned cast iron skillet is good) until just beginning to brown, about 2 minutes; spread apples in bottom of pan, pour batter over apples.
Bake until the pancake is golden brown and puffed, about 20 minutes; invert onto a large platter.
Sprinkle with remaining lemon juice; dust with confectioners' sugar.