Preheat the oven to 325°F (160°C). In a mixing bowl, combine graham cracker crumbs, sugar, and melted butter. Press the mixture into the bottom of a greased 9x13 inch baking pan.

In a large mixing bowl, beat the softened cream cheese until smooth. Add sour cream, sugar, eggs, vanilla extract, and cinnamon. Mix until well combined.

Pour the filling over the crust in the baking pan. Bake for 45 minutes or until the center is set. Remove from the oven and let cool.

In a small bowl, whisk together powdered sugar, milk, and vanilla extract until smooth. Drizzle over the cooled cheesecake.

Sprinkle with purple, green, and gold sugar to decorate.

Chill the cheesecake bars in the refrigerator for at least 2 hours before cutting into squares and serving.