Preheat the oven to 300°F. Line a muffin tin with 6 foil baking cups (the cakes will stick to paper liners). Lightly spray the liners with avocado oil spray.
Place the chocolate in a small bowl. Microwave it in 30-second intervals, stirring after each microwave session, until the chocolate is completely melted. Set aside.
In a medium bowl, using an electric hand mixer set to the lowest speed, beat the cream cheese, vanilla, and stevia until smooth. This should take no more than 30 seconds.
Add the melted chocolate and beat on low just until blended, scraping down the bowl with a rubber spatula as needed.
Add the egg and mix until just incorporated. Don't overmix.
Using a rubber spatula, give the batter one last mix to make sure everything is well incorporated.
Spoon the batter into the prepared muffin cups, smoothing out the tops. Bake until the centers of the cheesecakes are just a bit jiggly, about 15 minutes.
Place the muffin tin on a cooling rack. Let the cakes cool completely for about 2 hours before removing the liners and serving them.
Video
Notes
To ensure a smooth texture, all ingredients must be at room temperature. One option is to remove the cream cheese and egg from the fridge two hours before you plan to start mixing the ingredients. Alternatively, microwave the cream cheese for 30 seconds, and submerge the egg in warm water while you prep the ingredients.
Like all cheesecakes, these cakes are ready when they are slightly underbaked. In my oven, 15 minutes at 300°F is perfect.
Similar to other cheesecakes, they should be completely cool before you can enjoy them. Thankfully, there's no need to refrigerate them. They are perfect after cooling on a rack for about 2 hours.
Store these cakes in an airtight container in the fridge for up to 3 days. After that, they become less creamy and fluffy. Remove them from the fridge an hour before you plan on enjoying them. You can also freeze these cheesecakes for up to a month. Once they're completely cool, wrap each in plastic wrap and then place them in a freezer bag.