Melt about 5 white chocolate melting wafers in a microwave-safe bowl until smooth (this should take about 30 seconds to 1 minute). Use a small spoon or chopstick to drizzle thin lines or small drops of white chocolate onto each cavity of the mold, making sure to get the sides as well. Allow the chocolate to set (about 5 minutes) before adding the dark chocolate layer.

In a microwave-safe bowl, melt all of the dark chocolate wafers for about 1 minute and 30 seconds, or until fully melted. Stir until completely smooth and runny. Prepare your work area by laying down parchment paper to catch any excess chocolate. Place the mold on top. Pour a thin layer of melted dark chocolate into each cavity, then tilt the mold to coat the edges and sides. Turn the molds upside down to let any excess chocolate drip onto the parchment paper. Transfer the mold in the fridge until firm, about 10 minutes, while you prepare the filling.

Cut the kataifi into short pieces. In a large pan, melt butter then add kataifi. Toast for 5 minutes over medium heat until golden brown. Turn off the heat. Mix in the pistachio butter and tahini until fully combined.

Remove the molds from the fridge. Pour the pistachio filling evenly into each chocolate-coated mold, pressing lightly to pack it. Be sure to spread the filling into the edges as well.

Reheat the chocolate for about 30 seconds to make it runny again. Pour it over the pistachio filling, spreading it evenly to cover and seal each candy bar. Tap the mold gently on a flat surface, then carefully scrape off any excess chocolate to smooth the top layer. Place the mold back in the fridge for about 20 minutes or until the chocolate is fully set.

Once firm, pop each candy bar out of the mold. Score the edges to make removal easier. These are big candy bars, so it’s best to cut them into small pieces to share.