MAKE THE PIE CRUST: In a large bowl, whisk together the flour, sugar, and salt. Add the chilled butter cubes and use a pastry cutter or your fingers to combine until the mixture resembles coarse crumbs. Gradually mix in the ice water, one tablespoon at a time, until the dough just comes together. Divide the dough in half, flatten each into a disc, wrap in plastic wrap, and refrigerate for at least 30 minutes.

PREPARE THE PIE SHELLS: Preheat your oven to 375°F (190°C). On a floured surface, roll out one disc of dough to about ⅛ inch thick. Cut circles large enough to fit into a muffin tin or mini tart pans. Gently press the circles into the tins and refrigerate for 15 minutes to firm up. Dock the bottom of each crust with a fork, line with parchment paper, and fill with pie weights or dried beans. Bake for 10-12 minutes. Remove the weights and bake for another 5 minutes until lightly golden. Allow to cool.

MAKE THE CHOCOLATE FILLING: In a small saucepan, heat the cream over medium heat until just simmering. Remove from heat, add the chopped chocolate, and let sit for 2 minutes. Stir until smooth. Stir in the vanilla extract and butter until glossy. Set aside to cool slightly.

CREATE THE SHAMROCK TOPPERS: Roll out the second dough disc and use a small shamrock-shaped cutter to cut out shapes. Place the shamrocks on a lined baking sheet, brush with egg wash, and bake for 5-7 minutes, or until golden.

ASSEMBLE THE PIES: Pour the chocolate filling into the cooled pie crusts, smoothing the tops with a spatula. Place a baked shamrock cutout on top of each pie. Refrigerate for at least 2 hours, or until the filling is set.