Cake keeping hot with a hot dish(5)B?U?A
Bhuja is a spicy Indian dish, but doesn't fit with the wordplay. Bhuga fits with the wordplay,ie bug(a type of cake) about 'h' plus 'a', but I'm not sure it's a 'hot dish'.
There is a good selection of Indian restaurants where I live and they all offer a dish called a BHOONA but some of them spell it BHUNA - B(H)UN - A. A medium hot spicy dish.