Position a rack in the center of the oven, set a heavy-duty rimmed baking sheet on the rack, and heat the oven to 375°F.
In a medium saucepan over medium heat, melt the butter and cook, swirling the pan occasionally, until the butter is brown, 3 to 5 minutes. Immediately whisk in the brown sugar, corn syrup, and Lyle’s Golden Syrup until smooth. Remove the pan from the heat and let cool slightly. One at a time, whisk in the eggs. Whisk in the bourbon, espresso powder, vanilla, and salt. Stir in the chopped pecans.
Sprinkle half of the pecan halves in the piecrust, followed by the toffee candy pieces, and then the remaining pecan halves. Pour the syrup mixture over all.
Put the pie on the heated baking sheet and reduce the oven temperature to 350°F. Bake until set, 45 to 55 minutes, rotating the pan halfway through baking. When the pan is nudged, the center of the pie will no longer wobble, but the whole pie will jiggle just slightly, and the filling will bubble at the edges.
Transfer to a rack and cool completely before serving. The pie can be stored at room temperature for up to 2 days.
nutrition information (per serving):
49, Fat Calories
440, Saturated Fat
8, Monounsaturated Fat
87, Polyunsaturated Fat
Photo: Scott Phillips