Preheat oven to 175°C.

Grease a standard-size loaf pan with butter or line with with parchment paper.

Melt the butter and set aside to cool slightly.

In a large bowl, whisk together the flour, sugar, baking soda and salt. Add the chopped chocolate and half of the chopped macadamia nuts and whisk well to combine. Set aside.

In a medium bowl, lightly beat the eggs with a fork. Add the mashed banana, yogurt, melted butter and vanilla and stir to mix well.

Pour the banana mixture into the dry ingredients and stir gently with a rubber spatula, scraping down the sides as needed, unitl just combined. Do not overmix. The batter will be thick and somewhat lumpy, but there should be no unincorporated flour.

Scrape the batter into the prepared pan and smooth the top. Sprinkle with the left chopped macadamia nuts.

Bake until the loaf is a deep shade of golden brown (and the nuts are golden, too) and a toothpick inserted into the centre comes out clean,50 minutes to 1 hour.

Cool the loaf in the pan on a wire rack for 5 minutes, then tip it out onto the rack, and let it cool completely before slicing.. that was the difficult part, It was just amazing warm, with the chocolate still melting inside!