Step 1: Make the Crust Dough.

Put the flour in a large bowl. Gradually work in the shortening with a pastry cutter or two knives. The mixture should resemble coarse meal.

Beat the egg with a fork in a small bowl. Pour it into the flour mixture. This adds richness and binds the dough.

Add the cold water, vinegar, and salt. Stir until all the ingredients are combined. Don’t overmix.

Divide the dough in half. Form into two balls. Place each in a large resealable plastic bag.

Using a rolling pin, slightly flatten each ball of dough. Seal the bags. Place them in the freezer for 15 to 20 minutes to chill.

Chilling the dough is crucial. It makes it easier to roll out. It also prevents the crust from shrinking during baking.

Step 2: Prepare the Rhubarb Filling.

While the dough is chilling, prepare the filling. Toss the sliced rhubarb with the apricot jam, vanilla extract, and salt in a large bowl.

Whisk the sugar and cornstarch together in a small bowl. This ensures that the cornstarch is evenly distributed.

Add the sugar and cornstarch mixture to the rhubarb. Mix well to combine. Set aside.

Step 3: Roll Out the Bottom Crust.

Position a rack in the lower third of the oven. Preheat the oven to 425°F (220°C).

Roll out one piece of dough into a 12-inch round on a lightly floured surface. Start in the center and work your way out.

Sprinkle the dough with flour if it’s a bit too moist. If the dough is sticking to the surface, use a metal spatula to carefully scrape it up and flip it over.

Place the dough in a 9-inch pie plate. Do not trim the excess dough.

Step 4: Add the Filling.

Pour the rhubarb mixture into the pie plate. Spread it evenly.

Step 5: Roll Out and Create the Lattice Top.

Roll out the second piece of dough into a 12-inch round. Cut it into 12 even strips.

Lay 6 strips across the top of the pie, evenly spaced.

Gently fold back every other strip halfway.

Lay another strip of dough on the pie over the unfolded ones, perpendicular to them.

Unfold the strips so they lie over the perpendicular one.

Fold back the strips that haven’t been folded yet. Add another perpendicular strip. Unfold the strips over it.

Repeat the folding and unfolding process until you have a lattice. If the dough strips tear, gently press them back together.

Step 6: Trim and Crimp the Edges.

Trim the ends of the strips to be even with the edge of the pie plate.

Fold the overhanging bottom crust up and over the lattice strips. Trim any uneven areas.

Crimp the edges of the crust using your fingers or a fork. This creates a decorative seal.

Step 7: Brush and Bake.

Brush the lattice crust with heavy cream. Sprinkle with sugar.

Place the pie on a foil-lined baking sheet. Place on the lower oven rack.

Bake for 15 minutes. Then, reduce the oven temperature to 375°F (190°C).

Continue baking until bubbly and golden brown, about 45 minutes more.

Tent the pie with foil if it starts getting too brown. This prevents the crust from burning.

Step 8: Cool and Serve.

Let the pie cool completely on a wire rack before slicing and serving. This allows the filling to set. Cooling completely is essential.