Make the crust: Pulse the flour, sugar and salt in a food processor until combined. Add the shortening and pulse until the mixture looks like coarse meal. Add the butter and pulse a few times until it is in pea-size bits. Add the egg yolk and 2 tablespoons ice water, then pulse a few times. Pinch the mixture with your fingers; if it doesn’t hold together, add more water, 1 tablespoon at a time. Turn out onto a sheet of plastic wrap, gather into a disk and wrap. Refrigerate until firm, at least 1 hour or overnight.
Roll out the dough into a 12-inch round on a lightly floured surface and ease into a 9-inch pie plate. Trim the edges, leaving a 1-inch overhang. Tuck the overhanging dough under itself and crimp the edges with your fingers. Freeze until firm, about 30 minutes.
Meanwhile, position racks in the middle and bottom of the oven; preheat to 350˚ F. Spread 1 cup pecans on a baking sheet and toast on the middle rack until darkened, 8 to 10 minutes; let cool.
Line the pie crust with parchment or foil and fill with pie weights or dried beans. Bake on the bottom oven rack until the edges of the crust are lightly browned, 20 to 25 minutes. Remove the parchment and weights and continue to bake until the bottom of the crust is golden, 10 to 15 more minutes.
Meanwhile, make the filling: Melt the butter in a medium saucepan over medium heat and cook, swirling the pan occasionally, until brown flecks appear, about 8 minutes. Remove from the heat and whisk in the cream of coconut, brown sugar, flour, lemon juice and salt. Let cool to lukewarm, 5 to 10 minutes, then whisk in the eggs and coconut extract until combined.
If the crust has cooled, return it to the oven for a few minutes to warm through. Scatter the toasted pecans in the crust. Pour in the filling. Top with the shredded coconut and remaining 1/2 cup untoasted pecans. Bake on the middle oven rack until the filling is just set, 35 to 40 minutes (cover loosely with foil if the crust is getting too dark). Transfer to a rack to cool completely.