Preheat oven to 350°F (175°C) and prepare a 9x13 inch pan by greasing it lightly. Prepare the boxed white cake mix according to package instructions, pour batter into the pan, and bake for 25-30 minutes until golden. Allow cake to cool completely.

Once cool, cut cake into small cubes and portion them into 32 plastic dessert cups, filling each cup about two-thirds full.

In a large mixing bowl, combine the sweetened condensed milk, evaporated milk, whole milk, and vanilla extract. Whisk until smooth.

Gently pour the milk mixture over the cake cubes in each cup, pressing down lightly to saturate without breaking the cake.

In a separate bowl, pour heavy cream, add powdered sugar and vanilla. Whip on medium-high until stiff peaks form, about 3-5 minutes.

Pipe whipped cream onto each dessert cup and sprinkle with cinnamon if desired.

Cover and refrigerate for at least 3 hours, overnight preferred, to allow flavors to meld.