Preheat the oven to 325F and lightly grease a 10-inch oven-proof skillet (does not need to be cast-iron).
In a medium bowl, whisk together the almond flour, coconut, baking soda and salt. In a large bowl, beat the butter until creamy. Beat in the sweetener until well combined.
Beat in the egg and vanilla extract. Beat in the almond flour mixture until well combined, then stir in the chocolate chips.
Spread the dough in the prepared skillet and bake 20 to 25 minutes, until light golden brown. The cookie will be very soft and puffed when removed from oven (it won't seem cooked through).
Let cool at least 15 minutes before serving. When warm, it will not come out in proper pieces so you will need scoop it out to serve onto plates. It will continue to firm up as it cools so if you want to serve it in pieces, let it cool completely before cutting. I recommend it warm for extra gooey-ness!