Preheat oven to 180 degrees. Keep a silicon mat or a parchment lined tray ready.

Rub the zest into the sugar and add into the softened butter. Beat till creamy.

Add in the orange juice and yogurt and beat just till combined.

In another bowl, whisk the dry ingredients together. Tip the chocolate chips and toss.

Add this to the wet ingredients and beat briefly till the mixture comes together.

Using your hands, shape the dough lightly into a log and place it on the prepared mat or tray.

Bake for 30 minutes.

Take out the tray and leave the log to cool for 15 minutes.

Using a sharp knife, cut into neat 12 slices, around ½ to ¾ inch thick. It may be soft to handle, so cut gently without crumbling. Arrange the slices on the tray.

Bake again for another 15 to 20 minutes till done.

Transfer to a wire rack to cool completely.

Store in an air tight container and consume within 10 days.