To begin, preheat your oven to 350 and line two pans with parchment paper.
In a large mixing bowl, add your coconut oil, white sugar and brown sugar and beat with a mixer till creamy. Add your orange juice, orange zest, egg and vanilla and mix together again briefly.
To the same bowl, sprinkle in your flour, cornstarch, baking soda and salt. Stir until everything is well incorporated and you have a thick, smooth cookie dough. Add your white chocolate chips and gently fold them into your batter.
Using a small cookie scoop, scoop your cookie dough balls onto your pans, and spread them evenly apart (about 12 cookies to each pan). Bake in the oven for 10-12 minutes, or till the edges of the cookies are set and just gaining some color.
Let your cookies cool on the pan for at least 15 minutes, and then move them onto a cooling rack till they have cooled entirely.
Store your cookies in an airtight container, and they taste best within the first 4 days.