In a large bowl, combine flour, cocoa powder, sugar, and salt. Add cold butter and mix until crumbly. Stir in ice water until dough forms. Shape into a disc, wrap in plastic, and refrigerate for 30 minutes.

Bake the Crust

Preheat the oven to 350°F (175°C). Roll out the chilled dough and fit it into a 9-inch pie pan. Prick the bottom with a fork and bake for 15-20 minutes until set. Let cool.

Prepare the Filling

In a saucepan, heat heavy cream until just simmering. Remove from heat and add chocolate chips, stirring until melted and smooth. Allow to cool slightly.

Combine Eggs and Chocolate

In a mixing bowl, whisk together eggs and vanilla extract. Gradually add the chocolate mixture, stirring until smooth.

Bake the Filling

Pour the chocolate filling into the cooled crust. Bake for 25-30 minutes, or until the center is set but still slightly wobbly. Let cool completely.

Serve

Top the cooled pie with whipped cream made from powdered sugar and serve with vanilla ice cream.