The procedure:
Preheat oven to 350 F and roast the cashews, stirring every 5 minutes until golden brown and fragrant. Make sure to keep an eye on them as they will go from done to inedible very quickly. Set aside to cool. If using cashews that are already roasted, skip this step.

Increase oven temperature to 375 F.

Roll out dough base to 1/4″ to 1/8″ thick, depending on your preference and press into the base of a lightly-oiled, parchment-lined 8″ square pan. Prick the bottom lightly with a fork to prevent the dough from puffing up, then place the pan in the freezer for 15 minutes. After 15 minutes, partially bake the shortbread crust for 20 minutes while you prepare the topping.

Roughly chop the cashews. Combine the honey, brown sugar, and salt in a heavy saucepan, stir to combine and bring to a boil. Let it boil for 2 minutes without stirring, then add the butter and stir, allowing it to continue boiling for one more minute. It”s critical to keep an eye on your caramel to prevent it from burning.

Remove the caramel from the heat and quickly stir in the cashews, coating them with caramel. Pour the filling over the crust (which should still be hot from baking, as this allows the caramel layer to spread out easier), smooth out as best you can and pop it back into the oven. If it’s not completely smooth, don’t worry, as the baking will “liquefy” the caramel once again. It’ll all work out in the end.

Bake for 15 minutes (or until the filling is nicely caramelized and bubbling). Transfer to a cooling rack and wait until cool to slice (careful as it’s like molten lava fresh out of the oven.)