Preheat oven to 350 F. In a large bowl add the softened butter, brown sugar, and sugar. Mix well with a hand mixer or stand mixer until the sugar is well blended into the butter.

Add the egg and vanilla extract to the bowl and mix well to incorporate.

Add the oat flour, baking soda, and sea salt to the bowl and gently mix into the dough. You can use a mixer on low speed for this or a rubber spatula. Be sure not to overmix this step and only mix until no flour clumps remain.

Add the chocolate chunks and mini chocolate chips to the bowl and fold into the dough to disburse.

Use a large cookie scoop to scoop the dough into cookies on a parchment paper lined baking sheet. Leave at least 2 inches between each cookie so they have room to spread in the oven. Bake for 11 - 13 minutes until the edges are golden brown and the centers of the cookies are slightly set.

While the cookies are still warm, use a large circular cookie cutter to form the cookies into a perfect circle or use a fork to gently press the edges of the cookie towards the center. This is optional but helps to create a perfectly circular shape. Add a few more mini chocolate chips on top of each cookie (optional) and allow them to cool completely on the baking sheet.

Once cool, enjoy or store in an airtight container or cookie jar. They will keep for up to a week out on the counter.