Your liver cannot tel  2a3d  l the difference between white sugar, honey, hfcs, molasses, nor the sugar in a banana. The difference is that a banana also contains fiber to slow the sugar absorption and moderate the insulin spike. I would never replace an egg, butter, nor oils with a banana in an attempt to make a recipe “healthier.” That is just a way to take protein and fat out in order to add sugar. This is the opposite of what should be done for weight control. If the goal is to make the recipe taste good, then the banana can make sense.