Fit half of the pastry into a 9 inch pie plate; trim overhang to 1/2 inch. Combine apples, sugar, flour, mace and salt in a large bowl; toss lightly to mix. Spoon into pastry-lined pan. Dot with 2 tablespoons butter; sprinkle with lemon juice. Roll remaining pastry; cut slits for steam vents. Fir over filling, turning edges of crusts under and flush with rim. Flute to make standing edge.
Bake at 400 degrees for 50 minutes, or until pastry is golden.
Remove from oven. Melt the remaining butter in a small saucepan; stir in brown sugar and cream. Heat slowly to boiling and remove from heat. Stir in pecans; spread over top. Bake about 5 minutes longer or until topping bubbles and crust is richly glazed. Cool on wire rack for at least 1 hour before cutting.
Makes 8 servings.