In a medium sized heat proof bowl add the butter. Set the bowl in the microwave for about 30 seconds to mostly melt it.

Add the sugars, salt, and vanilla and whisk to combine. Return the bowl to the microwave for 30 seconds then whisk until the sugar and butter come together in one thick, shiny mixture.

Add the cocoa and whisk to just combine. Set the bowl in the microwave again for another 30 seconds. Whisk until a mass starts to form around the whisk and some of the liquid separates.

Crack in the egg and whisk until the mix is smooth and shiny. Add the oat flour and baking soda and use a rubber spatula to mix it fully in. Fold in the chocolate.

Cover the bowl with plastic wrap to completely seal it and leave it on the counter (at room temperature) for 20 minutes. Then transfer it to the fridge to chill for about four hours.

When ready to bake, you may want to take the bowl out of the fridge 10 minutes early so the dough can soften slightly (it’s easier to scoop). Preheat the oven to 350 F. Line two cookie sheets with parchment paper and scoop the dough onto the pan in mounds of 2 tablespoons per cookie (if you do smaller cookies the bake time will be less - keep an eye on them).

Bake the cookies until the edges are set, the middles are matte (not wet looking) - this will take about 12 minutes. Let the cookies cool on the tray for at least 5 minutes before moving them.