Combine dry ingredients for the crust in a bowl. Beat in the butter. Beat the egg with vanilla and salt, and blend in. Form the dough into a 10-inch pie pan.
Line the crust dough with aluminum foil and fill it with dried red beans or pie shell weights. Place the crust in the preheated 350-degree oven and blind-bake it with the beans for 10 minutes. (The beans/weights keep the sides from caving in and the bottom from bubbling up.)
Remove foil and beans and bake another five minutes. Remove and cool the crust. Reduce oven heat to 325 degrees.
With an electric mixer, blend condensed milk, cream, and egg yolks until they're noticeably thickened. Add orange and lemon juices and half of the zest. Blend well.
Pour this mixture into the pie shell and bake for 20 minutes. Remove and cool.
When the pie is warm room temperature, beat the egg whites in a grease-free bowl with the cream of tartar until peaks begin to form. Add sugar a little at a time, until completely blended, then add orange flower water or orange extract. Beat until stiff but not dry. Carefully fold in the remaining zest with a rubber spatula to distribute evenly. Spread the meringue on top of pie.
Return the pie to the oven at 350 degrees for five minutes, or until top is lightly brown. Chill several hours before serving.