Soften the butter, add to a mixing bowl, beat with the brown sugar and vanilla essence until light and creamy
Add the eggs to the mixing bowl and beat until combined
Sift the flour, baking powder and baking soda into the mixing bowl, beat until combined
Mash the bananas and add to the mixing bowl with half of the chocolate chips. Fold in to combine
Spoon the mixture into the muffin holes and top with the remaining chocolate chips
Bake in the oven for 20 minutes, remove the muffin tin from the oven and allow the muffins to settle for 2-3 minutes before removing them from the tins to completely cool on a wire rack