Preheat the oven to 175ºC.
Melt the coconut oil / butter.
In a mixing bowl whisk the egg and add the melted coconut oil / butter, maple syrup, yogurt, vanilla extract and mashed banana. Give it a great big stir.
In a second bowl mix the flour, baking powder, cinnamon and salt.
Add the dry ingredients to the first mixing bowl, and throw in the walnuts, coconut sugar and chocolate chips. Give it one last big stir, then pour into a loaf tin and sprinkle over the espresso powder.
Bake in the oven for 50 minutes. This loaf tastes its absolute best eaten warm from the oven, so enjoy!