In a large bowl using a handheld mixer, beat the cream cheese, brown sugar, granulated sugar and cornstarch on medium speed until creamy, about 1-2 minutes.
Scrape down the sides of the bowl and add pumpkin purée, sour cream, vanilla and pumpkin spice and continue beating until smooth.
Add eggs one at a time, beating slowly until just combined, do not overbeat. Fold in mini chocolate chips.
Scrape sides and bottom of the bowl with a rubber spatula to make sure everything is fully combined. Forcefully tap bowl on the counter a few times to release any air bubbles.
Fill each liner with ¼ cup of batter. You may have some batter left, so scoop an extra tablespoon of batter into each liner until it’s finished. These cheesecakes can be filled all the way to the top.
Bake in preheated oven for 18-20 minutes until the tops are puffed and look dry.
Remove from oven and allow to cool completely on a cooling rack.
Once cooled, cover with plastic wrap and refrigerate until firm and chilled, about 2-3 hours or overnight.
FOR THE DARK CHOCOLATE GANACHE:
Put the chocolate chips and cream into a medium heat safe bowl. Microwave in 30 second intervals, stirring after each until combined and smooth.
Spoon ganache over cheesecakes and return them to the refrigerator to set while you prepare the whipped cream.
