Combine oil, honey, chilli powder, garlic and hot sauce in a bowl; whisk together. Place chicken breasts in a large resealable plastic bag; pour in marinade and close bag. Marinate in fridge for 3 hours.
Preheat oven to 230 degrees C.
Place sweet potatoes on a baking tray. Place corn in a shallow baking pan. Brush with canola oil; season with salt and pepper. Cover pan with foil.
Bake in the preheated oven until corn is roasted and brown, about 25 minutes. Continue baking until sweet potatoes are tender, about 45 minutes more.
Allow corn and sweet potatoes to cool until easy to handle, about 20 minutes. Cut kernels from cobs of corn; transfer half to a blender. Peel and cube sweet potatoes; add to the blender. Add cream; puree. Transfer mash to a bowl; stir in the remaining corn. Season with salt and pepper. Cover and keep warm.
Preheat barbecue for medium heat and lightly oil the grill plate.
Remove chicken from bag and place on preheated grill plate; discard remaining marinade. Cook until no longer pink at the bone and the juices run clear, about 6 minutes per side. An instant-read thermometer inserted near the bone should read 74 degrees C.
Cut chicken breasts into 3 equal pieces; serve on top of sweet potato-corn mash.