Generously spray or butter 11 X 8 baking dish then line with parchment paper and generously spray parchment paper. Set aside.
Measure out all ingredients.
In a medium pot, on medium heat, combine the sugar, corn syrup, honey, water and salt to a boil, till it reaches 250 ℉.
Meanwhile in a stand mixer (using the whisky attachment), or with hand beaters, beat egg whites till stiff peaks form.
Once the sugar mixture reaches 250, add ⅓ of the mixture to the egg whites while machine is still running, drizzling slowly avoiding the beaters for 4 minutes.
Return the remaining sugar mixture to the heat until it reaches 310℉.
While the machine is still running, drizzle remaining sugar liquid avoiding the beaters and beat for 10 minutes.
Then, add the vanilla and butter, beat until combined, 30 seconds, then with a spatula, fold pistachos into mixture. The mixture will begin to harden so work quickly!
Pour nougat mixture into prepared pan and press down mixture with oiled hands.
Let stand for 2 hours then cut into squares and wrap in parchment paper.