Bake cake according to directions on box in a 9X13 pan. Allow cake to cool completely. Poke holes over the top of cake. ( I used a large straw)
Reserve 1/2 cup of Sweetened Condensed milk and pour the rest over the cake. Put cake in refrigerator for about an hour to absorb milk.
Combine ricotta cheese, mascarpone cheese and vanilla in a mixing bowl. Beat until smooth. Add powdered sugar and cinnamon, if using and mix until combined. Add reserved sweetened condensed milk and mix until combined.
When cake has absorbed milk, spread cannoli topping evenly over cake. Top with mini chocolate chips and sprinkle powdered sugar over the chips. Cover cake and allow to set in refrigerator for 2-3 hours. Cake will keep for 4-5 days,