Step 1

Preheat the oven to 375 degrees.

Step 2

For the meringue, separate the egg whites from the egg yolks. Set aside the egg yolks. The egg whites should be room temperature before beginning to prepare the meringue. Beat egg whites in a stand mixer or by hand if you prefer until soft peaks form (the meringue will stand, but will still look a little frothy). Add the cream of tartar, sugar, and vanilla to the egg whites while continuing to beat the egg whites. Continue to beating until stiff peaks form.

Step 3

For the filling, mix cocoa, flour, and sugar in a medium-sized sauce pan. In a separate bowl, whisk 4 egg yolks, salt, and milk. Stir the wet mixture into the dry ingredients in the saucepan. Cook at medium heat until thick, about 5 minutes. Stir in the chocolate chips, vanilla, and butter. Pour into pre-baked pie crust.

Step 4

Gently mound the meringue over hot filling being careful not to leave any gaps between the meringue and crust. Bake the pie in the 375 degree oven until meringue is golden brown, about 20 minutes. Be careful not to overcook the meringue. If your oven doesn’t brown very well, remove the meringue and use a torch to brown the peaks or increase the oven temperature to 500 degrees for one to two minutes to ensure browning, but not overcooking.

Step 5

Remove the pie from the oven and allow to cool. Once the pie is cool, tent tin foil over the top of the pie and place in the refrigerator for up to 12 hours. Make sure that the pie is cool before placing in the refrigerator or condensation will form on the meringue.