Turn slow cooker on HIGH
Add butter and melt
Add sugar and combine
Add cocoa and combine
Allow sugar to dissolve (approx. 10mins)
Place lid on WITH tea towel
Cook on HIGH for 1 hour
Add oats
Add sultanas
Combine
Replace lid WITH tea towel
Cook on HIGH for a further 15 mins
Pour/scoop mixture into 32x22x1cm baking tray lined with baking paper.
Flatten out evenly, pressing down firmly with back of a spoon to compact tightly in tray.
*add optional decorations here and press lightly onto muesli using back of spoon
Put into fridge to cool for around an hour
Take tray out
Remove muesli mixture with paper
Cut into even lengths
You can decorate with sprinkles or whatever you desire.