Press one of the pie crusts into a 9 inch pie plate.
In a large bowl, mix together the sugar, flour and cinnamon. Stir in the apples and spoon the mixture into the crust. Dot with 2 tablespoons of butter and sprinkle evenly with lemon juice.
Top with the remaining piecrust, folding the edges under, and crimping. Cut several slits in the top. Brush with egg wash.
Bake for 45 minutes on the lower oven rack, shielding with aluminum foil after 30 minutes to prevent excessive browning. Remove from oven, and let cool completely.
PRALINE TOPPING
Melt butter in a small saucepan; stir in the brown sugar and whipping cream. Bring to a boil over medium heat, stirring constantly; cook 1 minute, and remove from heat.
Stir in the pecans, and let stand 5 minutes. Slowly drizzle the mixture over the cooled pie.