Boil water on high heat for the steamer beforehand.
In a bowl, sift together the dry ingredients. Make sure to mix it well. Set it aside.
In another larger bowl, beat the eggs then combine mashed/pureed bananas and canola oil.
With a mixer, gradually add the dry ingredients until every last bit is blended.
Oil a baking pan or any type of container appropriate for steaming. (It doesn't really matter what shape it is as long as it fits the steamer and can also contain the batter leaving an inch allowance for puffing up.)
When the water boils, place the container and steam for 20 minutes.
Mix the ingredients for the sugar crumb topping. Mix well.
After 25 minutes, the cake has already puffed up. Spread the sugar crumb topping and continue steaming for 5 more minutes or until a fork or toothpick comes out clean when the middle part of the cake is poked all the way through.
Place on a rack and let it cool for about 20 minutes(or until you can resist the urge of devouring the whole thing). Enjoy!