In a large bowl, mash the bananas with a fork
Add eggs, vanilla, and butter/oil
Beat these wet ingredients together with a hand held beater (I use an electric one), the batter should become smooth, yellow and a little frothy
Add the flour and baking powder
Beat for a further 30-60 seconds to make a well-mixed batter
Portion into an oiled muffin tin (I use a non-stick silicon tray sprayed with oil) Mix makes 12 standard sized muffins or 30 mini muffins
Top the muffins with a blueberry or two
Bake at 180 degrees Celsius for 15 mins (360 Fahrenheit), 15 min cook time is based on making mini muffins, the mix makes approx 30 mini muffins. If you are using a standard muffin tray and making approx 12 muffins the cook time will be longer, approx 25-30 mins
Cool
Serve