Place the flour, cocoa powder, sugar, salt, and cubed butter into a large food processor. Pulse 15-20x until coarse crumbs form. Alternatively, you can use a large bowl and pastry cutter. Slowly drizzle in the cold milk or cream while pulsing (or stirring). After all the milk or cream is added, the dough should look slightly shaggy and be a little soft. If it’s too dry, add another Tablespoon of milk or cream. Try not to overwork the dough. Divide the dough in half and form each into 1 inch thick discs. Wrap each disc tightly in plastic wrap and refrigerate for 2 hours and up to 5 days.

On a floured work surface (you can “flour” with cocoa powder too!), carefully roll out each pie dough with a rolling pin. Cut into heart shapes (using a 3-inch heart cookie cutter). Re-roll any scraps. Refrigerate the hearts as you prepare the filling. (I make room and refrigerate them on 2 baking sheets.)

Place chopped chocolate into a large bowl. Heat the cream in a small saucepan over medium heat, stirring occasionally. Once it begins to boil, immediately remove from heat then pour over the chocolate. Stir gently and slowly using a wooden spoon until the ganache is smooth. Stir in peanut butter, if using. Allow it to cool for 15 minutes. During this time, it will slowly thicken.

Preheat the oven to 400°F (204°C).

Remove the hearts from the refrigerator. Arrange on 2 large baking sheets if you haven’t done so already. Brush the edges of half of the hearts with egg wash. Add a spoonful of filling on top of half of the hearts. Top with another heart (lightly stretch the top heart slightly if needed to cover). Press down the top edges to seal, then use a fork to crimp the sides to completely seal. Brush the top of each hand pie with egg wash. Top with coarse sugar, if desired.

Bake the hand pies for 15-18 minutes, just until the edges are set. The tops of the hand pies may look a little soft. Allow to cool for 10 minutes before drizzling with chocolate and serving.

Melt the chopped chocolate and oil (and peanut butter, if using) together in the microwave in 20 second increments, stirring after each until completely melted. You can also melt in a double boiler if you have one. Drizzle over pies.

Cover and store leftover hand pies at room temperature for up to 2 days or in the refrigerator for up to 1 week.