First, melt coconut oil until it becomes liquid (warm but not hot).

Add coconut oil, vanilla extract, egg yolk, salt, cane sugar, and sourdough starter to a medium bowl. Using a spoon, mix together until just combined.

Now add flour, sea salt, and baking soda. Using the back of your spoon combine all ingredients until you form a dough. Do not over-mix.

Place the dough covered in a small Tupperware or wrapped in plastic wrap. Be sure the dough is tightly sealed so it doesn’t become dry on the outside.

Ferment the covered dough at room temperature for 6-8 hours. You can either bake right away or transfer the covered dough to the fridge until you’re ready to bake, whatever works best for your schedule.

When you’re ready to bake, preheat your oven to 350°F (177°C).

Divide and roll the cookie dough into 10-12 cookies, depending on how large you want your cookies to be. I like each cookie to weigh around 20-30g. Press the middles down slightly and sprinkle a little sugar on top.

Bake for 6-8 minutes or until lightly browned on the sides.

Remove from the oven and let cookies fully cool on the baking sheet. Enjoy!

Store sourdough cookies in an airtight container at room temperature for 3 days or in the refrigerator for 6 days. To reheat, bake in a 350°F (177°C) oven for 5 minutes.