Add 1/4 cup pistachios to a food processor or chopper cup with an immersion blender. Pulse until finely chopped, but not completely powdered. Add 2 tablespoons cashew butter, 1 tablespoon tahini, 1 tablespoon coconut oil, 1/4 cup maple syrup, 1/2 teaspoon vanilla extract, and 2 pinches of salt. Blend until smooth and creamy, scraping down the sides as needed.
Place 2 cups of Corn Chex cereal in a sandwich bag and gently crush with your hands or a rolling pin until broken into small pieces but not completely pulverized. Transfer the crushed Chex to a mixing bowl.
Pour the pistachio mixture over the crushed Chex cereal and fold together with a spatula until well incorporated and every piece is coated. Line a 4x8-inch bread pan with parchment paper, leaving overhang on the sides for easy removal. Press the mixture firmly and evenly into the pan using the back of a measuring cup or your fingers.
In a microwave-safe bowl, combine 1/3 cup chocolate chips and 2 teaspoons coconut oil. Heat in 30-second intervals, stirring between each, until completely melted and smooth. Pour over the pistachio Chex layer and spread evenly with a spatula. Tap the pan gently on the counter to remove any air bubbles.
For the optional white chocolate drizzle, melt 1 tablespoon white chocolate chips with a small amount of coconut oil. For a green color similar to authentic Dubai chocolate bars, add a touch of oil-based green food coloring, 1/4 teaspoon spirulina powder, or a combination of spirulina and a dash of turmeric. Drizzle over the chocolate layer in a zigzag pattern. Sprinkle with additional chopped pistachios and a few pinches of coarse salt if desired.