In medium bowl, combine cashews and pistachios. In small bowl, mix oil, hot pepper sauce, chili powder, kosher salt, and cayenne pepper. Drizzle spice mixture over nuts; stir to coat evenly. Spread nut mixture onto cookie pan in a single layer.
Bake 10 to12 minutes stirring once after 5 minutes. Remove from oven; spread nut mixture over paper towels to cool completely. Place cooled nuts into medium bowl; set aside.
Line 12 x 18 in. cookie pan with parchment paper. Generously grease paper with butter; set aside. Meanwhile, over medium-high heat, combine sugar and water in medium saucepan, stirring until sugar is dissolved. (Use pastry brush dipped in water to wash sugar crystals down on sides of saucepan.) Continue cooking, without stirring, 20-30 minutes until sugar mixture turns deep amber in color and Candy Thermometer registers 300ºF. (Carefully watch sugar mixture, as it can quickly turn from amber to dark brown.)
Once sugar mixture reaches 300ºF, remove from heat; using greased wooden spoon, stir in nuts. Immediately pour brittle mixture into prepared pan. Using greased, large angled spatula, spread sugar mixture as thinly as possible. Cool completely. Break brittle into pieces.
Cook's Tips: Store brittle in airtight container at room temperature for up to 2 weeks. Make certain to grease utensils with butter prior to making the sugar mixture. Have them ready and at easy reach as candy quickly hardens.
Gift Giving Tip: The stained glass beauty of this brittle, deserves to be admired and shouldn't be wrapped under cover. Place several large pieces of brittle in individual Clear Party Bags.