Combine the dry crust ingredients in a small bowl.
Stir in the melted butter until the dry ingredients are wet.
Pour the crust mixture into a 9″ pie pan.
Press the crust into the pie pan with your hands, spreading the crust evenly around the bottom of the pan and up the sides.
Bake for 5 minutes. Remove from oven and let cool.
Turn the oven up to 400 F. Place the egg yolks in a small bowl.
Combine sugar and cornstarch in a medium saucepan.
Add water and place over medium heat.
Stir constantly until the mixture boils. The mixture will start to look clear and glossy and will feel a bit thicker.
Stir while the mixture boils for one minute.
Pour approximately half the mixture into the egg yolks and stir till combined.
Pour the egg yolk mixture back into the pan with the remaining half of the sugar/cornstarch mixture and stir constantly over medium heat for an additional 2 minutes (mixture should still be boiling).
Remove from heat and mix in the butter, espresso powder, and chocolate syrup until the butter is melted.
Pour the mixture into cooled pie crust.
Beat egg whites and cream of tartar on high speed until foamy.
Slowly and gradually add in the sugar, while continuing to beat at a high speed until the mixture becomes stiff and glossy. The topping is done when you can pull a beater out (when the mixer is off!) and the mixture holds a stiff peak.
Cover the top of the pie with the meringue spreading it all the way to the edges of the pie pan.
Bake for 12-15 minutes. The meringue will appear toasted. Allow the pie to cool, then cover and refrigerate. The pie can be served cold.