My mother called to tell me she made an amazing banana cake–the best ever!–she wanted to thank me for helping her convert the recipe from a margarine/butter-based recipe to an oil-based recipe. Instead of replacing the butter with oil in a one to one ratio, I told her to add slightly less oil than butter and make up the difference in volume with a little water.
Why? Because most butter is only about 81 percent butterfat (somewhere between 80 and 86 percent). The rest is water and milkfat solids. So 3/4 cup margarine is approximately equal to 10 Tbl. oil and 2 Tbl. water.
She also made a few of her own tweaks to the recipe–a little less sugar, a pinch more flour–and the result was a moist, but not greasy or heavy cake. My mom was thrilled: “Usually my banana cakes fall in the center or are heavy, but this cake was perfect!”
I was inspired to make the cake, too. My blender was on the counter, so I used that to mix up the batter. I decided to gild the lily by making a chocolate glaze with melted chocolate chips and coconut oil. The glaze tastes a bit like Magic Shell or the coating on ice cream bars. The flavor combination of cake and glaze is reminiscent of chocolate covered frozen bananas.
