Preheat the oven to 350 degrees F

In the base of a stand mixer, add softened butter and sugar. Cream sugar and butter together until the mixture is pale and fluffy. Then add in the flour, cornstarch, and salt. Pulse together the ingredients until they are just combined

Pat the shortbread into a parchment lined 9×13 pan until it forms an even layer

Bake for ~45 minutes until the crust is golden brown. Set aside to cool slightly while making the filling

After the crust is baked, make the filling

In the bowl of a stand mixer or with a hand mixer, beat together butter and brown sugar

After butter and sugar are well combined, add in the egg. Mix the egg and butter together until fully incorporated

Add vanilla, corn syrup, salt, bourbon, orange zest and mix. Set aside

Spread the nuts in an even layer over the golden shortbread base. Pour filling over top

Cook at 350 for 30 minutes (filling shouldn’t jiggle when shaken)

Allow the bars to cool

After the bars have cooled, drizzle with the melted dark chocolate and sprinkle with sea salt