Slice the stem ends off the strawberries, about ½ inch, revealing an opening in each berry. Use a narrow spoon to remove about half of the flesh inside each berry, allowing room for filling.
In a small bowl, mix ricotta, sweetener, and vanilla extract until uniform.
Spoon ricotta mixture into a bottom corner of a plastic bag; snip off the tip of that corner to create a small hole and squeeze the mixture into the strawberries. Top with chocolate chips.