Combine flour, sugar, and salt in a bowl or food processor. Add cold cubed butter and cold shortening. Pulse or cut in with a pastry cutter until mixture resembles coarse crumbs with pea-sized pieces of butter.

Add water and form

Sprinkle ice water over mixture 1 tablespoon at a time and gently mix until dough just comes together. Do not overwork. Gather into a disk, wrap in plastic, and chill in refrigerator for at least 30 minutes.

Roll and blind-bake

Preheat oven to 400°F (205°C). On a lightly floured surface, roll chilled dough into a 12-inch circle. Fit into a 9-inch (23 cm) pie plate, trim and crimp edges. Chill crust in freezer 10 minutes. Line crust with parchment and fill with pie weights or dried beans. Bake 15 minutes, then remove weights and parchment and bake another 8–10 minutes until golden and fully set. If desired, brush inside with beaten egg and return to oven 2 minutes for a shiny seal. Cool completely on a rack.

Coconut Pastry Cream Filling

Toast coconut

Spread 1 cup sweetened shredded coconut on a baking sheet and toast in the 350°F (175°C) oven for 5–8 minutes, stirring once, until golden. Remove and set aside to cool.

Heat milks

In a medium saucepan, combine whole milk and coconut milk. Warm over medium heat just until steaming and small bubbles form at the edges (do not boil).

Whisk eggs and dry ingredients

In a bowl, whisk together egg yolks, granulated sugar, cornstarch, and salt until smooth and pale.

Temper eggs

Slowly whisk about 1/2 cup of the hot milk mixture into the yolk mixture to temper. Then whisk the tempered yolks back into the saucepan with the remaining milk, stirring constantly.

Cook pastry cream

Return saucepan to medium heat and cook, whisking constantly, until mixture thickens and comes to a boil — about 2–4 minutes. Allow to boil gently for 30–60 seconds while continuing to whisk so the cornstarch fully cooks.

Finish cream

Remove from heat and stir in butter and vanilla until smooth. Fold in the toasted shredded coconut (reserve about 2 tablespoons for garnish) until evenly distributed.

Cool and chill

Pour pastry cream into a bowl and press plastic wrap directly onto the surface to prevent a skin. Chill until cold, at least 2 hours (or refrigerate until firm).

Assemble filling

When crust and pastry cream are fully cooled, spoon the chilled coconut pastry cream into the baked pie shell and spread evenly. Smooth the top. Chill pie in refrigerator while you prepare the whipped cream, at least 30 minutes to set.

Whipped Cream Topping & Garnish

Make whipped cream

Chill a mixing bowl and beaters if possible. Pour heavy cream into bowl, add powdered sugar and vanilla. Whip on medium-high speed until soft peaks form for a light topping, or stiffer peaks if you prefer a firmer decoration.

Top pie

Spread whipped cream over the chilled coconut filling with an offset spatula or pipe decoratively with a star tip. Sprinkle reserved toasted coconut and the 1/4 cup extra toasted coconut over the top, plus optional chocolate shavings if using.

Chill and serve

Refrigerate pie at least 1 hour after assembling to allow flavors to meld and topping to set. For best texture, serve within 2–3 days. Slice with a sharp knife dipped in hot water and wiped dry between cuts for clean slices.