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 9x13 pan until it forms an even layer
Bake for 45-55 minutes until the crust is golden brown
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 extract and vanilla bean paste, corn syrup, salt, bourbon, orange zest and mix. Set aside
Assembly:
Add chopped nuts onto 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 and drizzle with dark chocolate and sprinkle with sea salt