Cream together the butter and eggs, then mix in the ripe bananas and vanilla.
In a small bowl, mix the flour, salt, baking powder, and sugar together, then add to the wet ingredients and mix just until all is moistened. Add the walnuts and coconut.
Spoon the batter into muffin tins and bake at 350 for 30 minutes or so, until done. Alternately, pour into a buttered bread pan and bake about an hour.