Prepare the double pie dough recipe according to directions.
Divide into two discs, cover each one in plastic wrap and let chill in the fridge for about 1.5-2 hours.
Use one crust for lining the 9-inch pie pan and the second for creating decorative pie crust squares.
Roll out one crust to ⅛ inch thickness and line the pie pan. Cut off any overhanging crust.
Roll out second pie crust to ⅛ inch thickness. Use a ruler and sharp knife, cut out 1 inch by 1 inch squares.
Take a single square and very gently coat the bottom with a thin brushing of cool water. This will help the doughs to stick together.
Place the first square diagonally on the rim of the pie crust.
Repeat this process with the second piece covering half of the first. Continuing to layer squares around the rim of the pie.
Dock the bottom and sides of the pie crust with a fork.
Gently paint the square crust design with a thin coating of egg wash.
Place the pan in the fridge for 30 min to 1 hour, for the pie dough to chill and firm.
Chocolate Pie Filling
In a medium bowl combine the warm melted butter and both sugars. Stir until sugar has dissolved. Transfer to bowl of stand mixer.
Add egg yolks and mix on medium speed with paddle attachment.
Next, spoon in half the cocoa powder, espresso, vanilla, sweetened condensed milk, and heavy cream. Mix until smooth. Scrape bottom and sides of bowl as needed.
Add remaining cocoa powder and mix again.
Pour the chocolate filling into the cold prepared pie crust.
Place the entire pie back into the fridge for the filling to cool, about 15-20 minutes.
Bake Pie
Preheat oven to 350℉ (190 ℃), place pie on a thin metal cookie sheet. The cookie sheet helps to heat the pie pan and cook the bottom of the crust throughly.
Bake pie on the middle oven rack for 45-50 minutes until the crust is golden brown and a thin baked chocolate crust layer has formed across the top.
The pie center should be set. If there is a slight wobble in the very center, it will finish cooking as the pie cools.
Place pie on cooling rack until completely cooled.