Preheat oven to 350°F (175°C). Grease or line 24 mini muffin cups.
Combine the graham cracker crumbs and butter until thoroughly mixed. Divide among the muffin cups, using about 2 teaspoons of the mixture per cup. Press into the bottom and up the sides of each cup.
To make the filling:
Using an electric mixer on medium speed, beat the cream cheese, sugar, egg, and vanilla until thoroughly combined and smooth. Stir in the chocolate chips.
Divide the batter among the muffin cups, using about 1 tablespoon of batter per cup to fill the cups almost full.
Bake 18 to 22 minutes, or until the cheesecakes are set and the tops are lightly browned.
Cool the cheesecakes to room temperature. Then cover and refrigerate at least 4 hours before serving.
If desired, top with sweetened whipped cream and sprinkles.