Preheat the oven to 325° F. Line a muffin tin with paper or silicone liners.
In the bowl of a stand mixer or with a hand mixer, beat the cream cheese, eggs, Swerve, vanilla, and salt until smooth and fluffy.
Transfer all but ¼ cup of the mixture to the prepared muffin cups.
Add the cocoa powder to the bowl with the remaining mixture and whisk until smooth.
With a spoon, divide the chocolate mixture between the muffin cups and swirl.
Bake until set, about 30 minutes.
Allow to cool to room temperature and then refrigerate until chilled, about 2 hours.
If desired, top with whipped cream or berries and enjoy!