For the prep work, we will 'grease' each of the ramekins with the softened butter or oleo. Then sprinkle them with the granular sugar alternative (1 tablespoon at the most per ramekin), until they are covered. You may need to rotate the ramekin to disperse the sugar alternative more evenly. Also, warm your air fryer on a low setting (325-330).
Next, we will melt the chocolate. Use a microwave safe bowl (medium sized) to microwave, stirring every 30 seconds until melted. Alternatively, and actually preferably for the chocolate, use a double boiler method with simmering water on the bottom of the bowl. The bowl that holds this melted chocolate have additional ingredients added to it in later steps.
Now, we will melt that 1 ½ tablespoons of butter over low-medium heat. Use a small sized skillet. When the butter has melted you can whisk in the flour. It will take this a few minutes to thicken but, keep whisking until it does. When it does thicken you can remove this skillet from the heat.
You will be multi-tasking in this step. We will be combining the ingredients in the melted chocolate bowl while you whip your egg whites. Place the egg whites and the cream of tarter in a stand mixer with a whisk attachment. While the egg whites are whisking in order to form peaks, you can return to the butter and flour mixture. Add the melted butter and flour mixture to the melted chocolate and blend. Then stir in the egg yolks, vanilla extract and remaining sugar alternative. Watch the mixer with the egg whites. Once you get peaks forming in the egg whites you can stop the whisking and gently fold the egg whites into the bowl with the other ingredients.
Fill the ramekins with the batter about ¾ full. Then run your finger around the lip of the ramekin (a trick some folks use). Bake the souffles for 12-14 minutes or until done