Preheat oven to 325 degrees F (165 degrees C). Line a baking sheet with parchment paper.
Combine coconut oil, brown sugar, and white sugar in a large bowl; beat with an electric mixer until creamy. Beat in egg and vanilla extract.
Mix flour, baking soda, and salt together in a bowl. Gradually beat into the coconut oil mixture until just blended. Fold chocolate chips and oats into the dough.
Roll 2 tablespoons of dough into a ball. Place on the prepared baking sheet. Repeat with remaining dough, spacing balls about 2 inches apart.
Bake in the preheated oven until cookies are golden on the bottom, 12 to 14 minutes.