Preheat the oven to 325°F (165°C). Line a 12-cup muffin tin with cupcake liners.
In a medium bowl, combine the graham cracker crumbs, granulated sugar, and melted butter. Mix until the crumbs are evenly coated.
Divide the crumb mixture evenly among the 12 cupcake liners, pressing down firmly to create an even crust layer. Bake for 5 minutes, then set aside to cool slightly.
For the Cheesecake Filling
In a large bowl, beat the softened cream cheese with an electric mixer until smooth. Add the granulated sugar and continue to beat until well combined.
Add the eggs one at a time, beating well after each addition. Mix in the vanilla extract and sour cream until smooth and creamy.
Divide the cheesecake batter evenly into three bowls. Tint one bowl with yellow food coloring, one with orange food coloring, and leave the remaining bowl plain.
Spoon a layer of yellow cheesecake batter into each cupcake liner, followed by a layer of orange, and finally a layer of plain batter.
Bake for 18-20 minutes, or until the centers are set. Allow the cheesecakes to cool in the pan for 30 minutes, then transfer to the refrigerator to chill for at least 4 hours or overnight.
For the Orange Frosting
In a large bowl, beat the softened butter with an electric mixer until light and fluffy.
Gradually add the powdered sugar, beating until smooth and well combined.
Add the heavy cream and vanilla extract, and beat until the frosting is light and fluffy. Tint with orange food coloring.
Once the mini cheesecakes are fully chilled, remove them from the liners and frost the tops with the orange frosting.
Sprinkle the white sprinkles over the frosted cheesecakes.
For the Sugar Paste Ghosts
Roll out the white sugar paste or fondant and cut into small ghost shapes using a cookie cutter or freehand with a knife. Use black food coloring or an edible marker to add eyes and mouths to the ghosts.
Place a sugar paste ghost on top of each frosted cheesecake.
Serve immediately or store in an airtight container in the refrigerator for up to 3 days.