Preheat oven to 180C℃ (160℃ fan forced) . Line the base and sides of a 12cm x 22cm medium size loaf pan with baking paper.
Place the bananas into a large bowl. Using a fork, mash until roughly smooth. Add the eggs, buttermilk and oil and whisk until well combined. Add the caster sugar, brown sugar and vanilla extract, mix well.
Sift in the flour, bi-carb and salt. Using a spatula, fold to combine. If using add-ins like coconut, nuts or choc-bits etc gently fold them in now.
Pour mixture evenly into prepared pan. If using the extra banana on top, place it on now. Bake in the oven for 1 hour 10-15 minutes or until cooked when tested with a skewer. This can sometimes take a shorter or longer cooking time, depending if you add extra add-ins. Start checking around the 1 hour 10 minute mark.
Remove from oven and drizzle over honey or golden syrup, then using a pastry brush, brush over to coat the top. Cool in pan for 10 minutes before transferring to a wire rack to cool completely. Cut into 12 slices to serve.