Crumble the cooled cake into fine crumbs in a large bowl, until no large chunks remain.

Add the cream cheese frosting and cinnamon, and mix until the crumbs clump into a moist, uniform dough.

Roll into 30 balls, about 1 tablespoon each, pressing firmly so they hold together.

Place on a parchment-lined tray and freeze 15 minutes, until firm to the touch.

Melt the white chocolate in a microwave-safe bowl in 30-second bursts, stirring between each, until smooth.

Dip each ball into the melted chocolate with a fork, turning to coat completely, then tap off excess.

Set the dipped balls back on the tray.

While the chocolate is still wet, sprinkle each with a stripe of purple, green or gold sanding sugar, alternating across the batch.

Refrigerate 30 to 45 minutes, until the shell is fully set and hard to the touch.

Keep chilled until serving, and let sit at room temperature 5 minutes before eating.