Filling: Add the butter to a large saute pan and melt. Add the apples, sugar, cinnamon and lemon juice. Cook over medium heat until the apples are soft, about 15 minutes. Remove from the heat and cool.
When the filling is cool, roll the biscuits out on a lightly floured surface so that each biscuit forms a 7 to 8-inch circle. Place 2 to 3 tablespoons of the filling on each biscuit circle. Brush the edges of the circle with water. Fold the circle over the filling to make a half-moon shape. Seal by pressing the edges with a fork.
Preheat deep-fryer with oil to 350 degrees F.
Carefully add the pies to the oil, 1 at a time, and fry until golden brown, turning the pies as necessary for even browning, about 5 to 8 minutes. Drain on paper towels. Sprinkle with powdered sugar immediately.