As soon as the chocolate is on the rice cakes, divide 20 g Freeze dried berries and 1 teaspoon Ground nuts/seeds mix over the chocolate before it sets so that the toppings stick to it.
Notes
Sometimes when you are using very dark chocolate, it can be hard to melt and it will start to "seize". Add a little coconut oil to it, which will not only help it to melt, but it will make it nice and glossy too.
You need to work quickly when making these rice cakes covered in chocolate, because the chocolate will set quickly as it's only thin. You need to get the toppings on before it sets, so they stick.
To keep these rice cakes dipped in chocolate simple, you could just sprinkle some sea salt on the melted chocolate - the salt brings out the sweetness of the chocolate.