Preheat the oven to 200° and prepare 12 muffin tins on the baking sheet or in pie tins.
Mash the bananas and beat the eggs with oil in a bowl and reserve.
In another platter, mix the dry ingredients: wheat flour, sugar, bicarbonate, baking powder and salt, gradually incorporating the egg mixture into the flour (it will be a very pasty dough).
Then add the mashed bananas and mix well.
Place a slice of banana in each unit, sprinkle brown sugar over the top of the muffins before baking.
Note: this makes them crispy on top.
Distribute in the molds and bake for about 20 minutes until golden, or until a toothpick comes out clean.