Line a baking tray with baking paper, grease the tray first with a little butter to help the baking paper stick to it. You don't want it moving around when you're trying to spread out the chocolate. I used a tray that was 38.5 x 25.5 cm (15 x 10 inches)
Melt the dark chocolate, you can use a double boiler or melt in the microwave. I blast it on high for 30 seconds, then stir. Then continue with 10 second blasts, stirring between each one. If you chop the chocolate up or use chocolate chips it will melt a lot faster. Add the black food colouring to it and mix in well
Then melt the white chocolate following the same method. Add the orange food colouring to it and mix in well
Pour the dark chocolate out onto the lined baking tray, use a palette knife or the back of a spoon to spread it out. Give the tray a shake and tap it on the work surface a few times to help the chocolate smooth out, and remove and air bubbles
Add the orange coloured white chocolate in spoonfuls all over the top of the dark chocolate
Using a cocktail stick or a butter knife, swirl the two chocolates together
Decorate with your chosen sweets, chocolates, candy and sprinkles
Leave to set at room temperature, or set in the fridge
When fully set, remove from the tin and place on a chopping board. Use a large sharp knife to chop it into chunks, or snap it apart by hand
Leftovers can be stored in an airtight container in a cool place, for as long as the best before dates on the chocolate and toppings used