Add 150 g Chocolate (dark), 150 g Chocolate (milk), 70 g Butter and 3 tablespoon Golden syrup to a large microwave safe bowl. Microwave on high for 30 second intervals, until all the chocolate and butter have melted. Leave to stand for 1 minute.
Add 120 g Digestive biscuits and mix well.
Add 200 g Mini eggs (broken) and mix well again.
Add 60 g Mini marshmallows and mix one more time.
Line a 10x8" (25x10cm) baking tin with baking paper. Pour the mixture into the tray and press the mixture down and into the corners. Top with 100 g Mini eggs (whole), pressing them gently into the mixture. Refrigerate for 1 hour then cut into squares.
Notes
Our microwave is 1,000 watt, which melted the chocolate and butter in 90 seconds. Different microwaves may take longer, but keep doing it in 30 second intervals until fully melted. Don't cook it for too long in one go, as it can cause it to split. You can melt it in a bowl over a pan of water if you prefer.
Leaving the melted chocolate to stand for 1 minute is important as it will prevent the marshmallows from melting.
Use mini eggs with hard centres. Using soft centred eggs (like caramel or fondant) will melt into the chocolate mixture. Although you could use mini creme eggs and freeze them first before mixing them in.
Cutting mini eggs with a knife is near impossible. We put ours in a zip-loc bag and broke them up with a rolling pin.
Make sure to use vegetarian marshmallows if you want to keep this vegetarian. You can leave the marshmallows out and it is more of a tiffin.
Don't crush your digestives too small, you want to have some big chunks in there.
You need to press the rocky road well into the tin so it is nice and compact. You can use the back of a wooden spoon to do this.