Turn the oven on to 350 degrees. Line(parchment paper) a sizable baking sheet.
To a mixing dish, add butter and keto brown sweetener. For one to two minutes, beat at high speed to thoroughly integrate.
Beat on medium speed while adding the egg and vanilla. It's okay if the batter appears a little disjointed at this phase.
On low speed, add the salt, baking soda, almond flour, and coconut flour; scrape down the bowl's edges as necessary.
Add the chocolate chips gradually while mixing at low speed, just until they are distributed evenly.
Use a 1/3 cup measuring cup to generously scoop out the cookie dough, shape six large dough balls, and arrange them on the baking sheet. Add any extra dough evenly among the six dough balls if you have any. The dough balls should now be gently flattened and shaped into "hockey pucks."
When baking the cookies, turn the pan over after 10 to 11 minutes. Avoid overbaking. They will have a subtle brown tinge to the top and margins.