Combine the graham cracker crumbs, ground pecans, 2 tablespoons white sugar, 2 tablespoons brown sugar, and the melted butter or margarine and mix well. Firmly press mixture into one 9 inch springform pan.
Combine 3/4 cup of the white sugar, the pumpkin, 3 egg yolks, ground cinnamon, ground mace, ground ginger and salt in a medium bowl. Mix well, and set aside.
Beat cream cheese with an electric mixer until light and fluffy; gradually add 1/4 cup plus 2 tablespoons white sugar and mix well.
Add the whole egg, remaining egg yolk and the whipping cream, beating them well.
Add cornstarch and vanilla and lemon flavorings, beat batter until smooth.
Add pumpkin mixture and mix well. Pour batter into the prepared pan.
Bake at 350 degrees F (175 degrees C) for 50 to 55 minutes. Do not over bake.
Center may be soft but it will firm up when chilled.
Let cheesecake cool on a wire rack, then refrigerate.