Preheat oven to 350°F. Spray a 9x13 inch baking pan with nonstick cooking spray.

In a large mixing bowl, combine the cake mix with the eggs, oil, and water according to package directions. Stir in the ground cinnamon until the batter is smooth.

Pour the batter into the prepared pan and bake for 25-30 minutes, or until a toothpick inserted in the center comes out clean.

While the cake is still warm, use the handle of a wooden spoon to poke holes all over the surface, spacing them about an inch apart.

Pour the entire can of sweetened condensed milk over the warm cake, allowing it to soak into the holes. Let the cake cool completely.

Using a hand mixer or stand mixer, beat the softened cream cheese and butter together until light and fluffy.

Gradually add the powdered sugar, vanilla extract, and heavy cream. Beat on high until the frosting is smooth and spreadable.

Spread the frosting over the cooled cake.

Sprinkle purple, green, and gold sanding sugars in alternating diagonal stripes across the top for a classic Mardi Gras look. Optionally, hide a small plastic baby in one slice before serving.