In a medium sized large bowl mix together the flour, soda, and salt.
In a separate bowl whisk together the eggs, oil, water, and sugar.
Add the wet ingredients into the dry, stirring to combine completely.
Mash the bananas, then stir them into batter.
Place the oat bran in a food processor or chopper and pulse to break into small piece. The chunks should be no larger than peas.
Place the oat bran, along with the coconut, flour, and butter in a small bowl.
Use your fingers or a pastry cutter to incorporate the butter into the oat bran, flour, and coconut.
The final texture should resemble cooked ground beef.
Heat your oven to 350 degrees.
Grease your muffin pans using butter or cooking spray.
Scoop the batter into the muffin pan, filling each impression about ¾ of the way full.
Top with the streusel mixture, spreading it evenly among all the muffins.
Bake in a 350 degree oven and for 35 - 45 minutes for large muffins. (See note.)
