Special equipment: a 9-inch round pie plate; a ruler; 1-, 2- and 3-inch star cutters; Father's Day Pie Stencil (link below) or D and A letter cutters; one 8-inch lollipop stick; a sharp knife or molding stick, optional; a lifter or palette knife
For the pie pastry: Pulse the flour and salt in a food processor fitted with a metal blade until combined, 2 to 3 times. Scatter the butter and shortening over the flour mixture. Pulse 4 to 5 times until the mixture resembles small pebbles with a few larger pieces. Sprinkle 6 tablespoons of the ice water over top. Pulse until the mixture starts to clump and comes together, 6 to 8 times. If the mixture does not clump, add more water, 1 tablespoon at a time, pulsing 1 to 2 times between additions.
Turn the mixture out onto a lightly floured work surface. Cup your hands around the dough to bring together in a ball. Divide the dough into 2 balls, wrap each tightly in plastic wrap and chill for 1 hour.
For the dry rub and ribs: Preheat the oven to 400 degrees F.
Stir the cumin, chili powder, mustard, garlic powder, salt and pepper in a small bowl until combined. Set aside.
Rinse and pat dry the ribs. Rub both sides of the ribs with the dry rub. Place each rack of ribs, fat-side up, on a sheet of aluminum foil and seal shut. Place the packets on a sheet pan and bake for 90 minutes. While the ribs are baking, make the sauce.
For the rib sauce: Put the olive oil in a small saucepan and set over medium heat. When it begins to shimmer, add the onions and saute until soft and translucent, about 5 minutes. Add the chipotle powder to the onions and stir until warmed and combined. Add the ketchup, molasses, brown sugar, Dijon mustard and Worcestershire sauce to the pan. Stir to thoroughly combine. Bring to a simmer, reduce the heat to low and simmer for 10 minutes, or until the sauce is nicely thickened. Allow the sauce to cool slightly before using.
For the rib filling: When the ribs are done, make a slit in the top of each foil packet to allow steam to escape. Carefully open the packets (they will be hot!) and transfer the ribs to a wooden board. Using 2 forks, separate the meat from the bones and gently pull the meat apart. Place the shredded pork into a large bowl (discard the bones). You should have approximately 5 cups of shredded pork.
Add the rib sauce, shredded potato and cheese to the bowl. Mix gently until the ingredients are combined.
To create the floorboard design for the pie top: Line a large work surface with parchment paper. Lightly flour the work surface and a rolling pin. Roll out one batch of chilled dough to a 12-inch circle. Turn a 9-inch pie plate upside down and, using a sharp knife, cut a circle of dough to match the circumference of your dish. Re-wrap any leftover pastry scraps and return to the refrigerator.
Use a ruler to mark horizontal lines 1 inch apart on the dough circle. Lay a lollipop stick down at these marks to make horizontal impressions in the dough. Next, mark vertical lines in a staggered brick style across the pastry. Bend the lollipop stick at the 1-inch mark and use the 1-inch piece to make impressions at these points. Use the end of the lollipop stick to make circular indentations at the top and bottom of both ends of each plank to form nail marks. Use a sharp knife or molding tool to create wavy freeform lines across the pie. Transfer the finished pie top on the parchment paper to the refrigerator to firm up for at least 15 minutes.
To assemble the pie: Lightly flour your work surface and rolling pin. Roll out the second batch of dough to a 12-inch circle. Gently roll the dough up around your rolling pin and transfer it to the pie plate. Unroll the pastry over the pie plate and fit gently into the pan.
Transfer the rib filling to the lined pie plate. Gently flatten the top of the filling so it even with the top of the pie plate.
Position a rack in the lower third of the oven. Preheat the oven to 425 degrees F.
Remove the patterned pie top from the refrigerator. Using a brush, dampen the edges of the pastry-lined pie plate. Gently slide a lifter or palette knife between the pie top and the parchment paper to separate. Tilt the parchment paper to slide the pie top into place on top of the pie. Press gently on all edges to seal.
To create the pie decorations: Print out the Father's Day Pie Stencil (link below) and cut out the letters with scissors (or use D and A letter cutters). Roll out the leftover pastry scraps. Use the letter stencils or cutters and a sharp knife to cut out 2 Ds and one A.
Cut out 1 star using a 3-inch star cutter. Place the A on the star. Cut out 5 stars with a 1-inch star cutter and place on the points of the big star. Form the word DAD across the center of the pie. Use 1- and 2-inch star cutters to cut out additional 1- and 2-inch stars and place decoratively above and below the letters.
Use the leftover dough to create a rope border. Dampen the edges of the pie top and adhere the rope to the pie top. Brush the entire pie with egg wash. Bake for 12 minutes. Reduce the temperature to 350 degrees F and bake for another 45 minutes until the pie crust is golden.