Preheat the oven to 350°F.

In a small mixing bowl, combine the melted butter with the Oreo cookie crumbs until crumbly. Press the mixture into a 9-inch pie plate covering the bottom and sides.

Bake for 10 minutes. Remove from oven and cool completely.

In a medium saucepan, whisk together sugar, cornstarch, cocoa powder, and salt.

Add milk and whisk constantly over medium heat until warm but not boiling, about 3 to 4 minutes.

Add egg yolks and whisk constantly.

Bring to a boil and remove from heat immediately. The mixture will thicken quickly.

Pour mixture through a sieve into a bowl, discard large chunks.

Immediately add chopped chocolate and butter, whisk until smooth.

Pour the chocolate mixture into the baked pie crust.

Arrange candy corn decoratively over the top of the pie in a single layer.

Chill the pie for 30 minutes before slicing and serving.