Preheat the oven to 175 C. Line a baking tray with a silicone baking mat or baking paper.
In a mixing bowl, stir the yoghurt and butter together, then add the vanilla and honey. This mixture won't fully combine, don't worry about it.
Now stir in the sugar and oats. Then sift in the flour, baking soda, cinnamon and salt (if using). Fold gently to combine.
Finally, stir in the chocolate chips, using a little elbow grease to work them into the dough as it's quite thick.
Use a cookie scoop or your hands to divide the dough into 12 to 14 equal portions. Place an inch apart on the baking tray and flatten the tops, as these cookies don't spread a lot while baking.
Bake for 10 to 12 minutes, until puffy and lightly browned. Set aside to cool for ten minutes, then transfer to a wire rack to let them cool completely and firm up.
Once fully cooled, store in an airtight tin at room temperature for 4 to 5 days and in the fridge for about 10 days. Oats absorb a lot of moisture, so in humid environments, the cookies will go soft by day two. They'll still taste great though! Happy baking :)