Preheat the oven: Preheat to 325°F (163°C). Lightly grease a 9-inch springform pan.
Prepare the crust: Mix the graham cracker crumbs, melted butter, and sugar. Press firmly into the bottom of the pan. Bake for 8–10 minutes, then let cool slightly.
Make the filling: Beat the softened cream cheese and sugar until smooth. Add the eggs one at a time, mixing on low speed. Add the sour cream, vanilla extract, and flour. Mix until just combined.
Fill the pan: Pour the cheesecake filling over the prepared crust and smooth the top.
Bake: Bake for 50–60 minutes, until the edges are set and the center still has a slight wobble.
Cool gradually: Turn off the oven, leave the door slightly open, and let the cheesecake rest inside for 30 minutes. Remove and cool to room temperature.
Chill: Cover and refrigerate for at least 6 hours or overnight, until completely set.
Decorate: Remove the cheesecake from the springform pan. Pipe green buttercream into Christmas tree shapes on top. Add red and green candies, edible stars, and sugar pearls.
Serve: Slice with a warm, clean knife and serve chilled.