The night or several hours before, take all the ingredients out of the fridge and let them come to room temperature.
Make the blackberry sauce by pureeing the 16 oz of blackberries and adding them to a medium pot. Add the sugar and the juice and cook on medium-high heat for 10- 15 minutes. You are looking for a sauce/coulis consistency, not a jam. Remove from heat and strain if you don't like seeds and let cool.
Make the Oreo crust—Preheat the oven to 325 degrees. In a food processor, pulse the Oreo cookies and the melted butter until it's well mixed.
Prepare a muffin tin with liners, or press about one tablespoon of the cookies into each of the silicone muffin tin—Bake for 5 minutes. Let cool completely before adding the cheesecake batter.
Make the cheesecake batter. In and clean and dry food processor, blend the cream cheese, mascarpone, and sour cream together until light and well-whipped. Add in the sugar, salt, and extracts and blend until well mixed. Add the eggs and mix until just combined. Lastly, add 1/2 cup of the blackberry sauce and pulse until combined.
Fill the muffin tin almost all the way up with the batter. They will grow a little in the oven. Bake for 17-20 minutes or until the center is just set and is still a little wiggly. You want to take it out before the sides start to brown. Let them cool in the tray at room temperature for 1 hour, and then chill in the fridge for 3-4 hours.
Serve with the remaining blackberry sauce on top.
Notes
Have ALL of your ingredients at room temperature. This is the biggest thing to ensure a perfect texture, and it helps the mini cheesecakes from shrinking and breaking. I leave all of my ingredients out overnight.
Start with the blackberry coulis so that it has cooled by the time you are ready to make the cheesecake. It can also be made up to 5 days in advance.
Use a food processor to mix the cheesecake batter. This will help ensure a super creamy texture. If you don't have a food processor, a mixer works too.
Use a muffin silicon mold or line a muffin pan with cupcake liners so that the cheesecakes are easy to remove
Let the cheesecake cool at room temperature for an hour, and then chill in the fridge for 3-4 more hours.