How to Make It
Make the crust In a food processor, pulse the 1 1/4 cups of flour with the sugar and salt until combined. Add the butter and lard and pulse until the mixture resembles coarse meal. Drizzle the ice water on top and pulse until the dough just comes together. Turn the dough out onto a work surface, gather any crumbs and pat into a disk. Wrap in plastic and refrigerate until well chilled, about 4 hours or overnight.
On a lightly floured work surface, roll out the dough to a 13-inch round. Ease the dough into a 9-inch deep-dish pie plate. Fold the overhang under itself and crimp decoratively. Freeze the crust until well chilled, at least 1 hour.
Preheat the oven to 375° and put the crust on a large rimmed baking sheet. Line the crust with parchment paper and fill with pie weights or dried beans. Bake for about 20 minutes, until the crust is just set. Remove the parchment and weights. Bake for about 15 minutes longer, until just starting to brown. Let cool completely.
Make the filling Preheat the oven to 350°. Spread the pecans and walnuts on a large rimmed baking sheet. Toast in the oven for 8 to 10 minutes, until fragrant and lightly browned. Let cool.
In a medium skillet, cook the butter over moderately low heat, stirring occasionally, until foamy, about 5 minutes. Continue to cook, stirring frequently, until the milk solids turn brown and the butter smells nutty, about 4 minutes longer. Strain the brown butter through a fine sieve into a heatproof bowl. Let cool to room temperature.
In a large bowl, beat the eggs with the cooled brown butter, sugar, cane syrup, bourbon, salt and vanilla until smooth. Stir in the pecans and walnuts.
Pour the filling into the cooled crust. Bake for about 45 minutes, until the filling is nearly set. Transfer the pie to a rack and let cool completely, about 4 hours. Cut into wedges and serve with unsweetened whipped cream.