Put the dark chocolate in a large bowl and microwave at 50% power for 30 seconds. Stir well, even if the chocolate doesn’t appear to have melted. Repeat, microwaving for another 30 seconds at 50% power and stirring well after 30 seconds. Continue until all the chocolate is fully melted. Repeat with the white chocolate.Stir 1/2 cup of the cashews into each bowl.Spoon both melted chocolates onto the parchment paper to make a marbled pattern.Chill until set, then break into pieces. If your kitchen is cool, you can try to let it set at room temperature, but this will take much longer.
