1. Bake cake according to directions on box for a 9×13 pan.
2. Remove cake from the oven and poke holes all over the top of the cake. (I used a straw)
3. Reserve half a cup of sweetened condensed milk and pour the rest of the sweetened condensed milk over the cake.
4. Put cake in refrigerator for about an hour to absorb milk.
5. Combine ricotta cheese, mascarpone cheese and vanilla extract in a mixer bowl. Mix until smooth.
6. Add powdered sugar and cinnamon, if using and mix until combined.
7. Add reserved sweetened condensed milk and mix until combined.
8. Once cake has absorbed milk, spread cannoli topping evenly over cake.
9. Top with mini chocolate chips and a sprinkling of powdered sugar.
10. Cover cake and allow to set in refrigerator for 2-3 hours. Cake should keep for 4-5 days.
Do consider straining the ricotta before using, especially if it’s a particularly watery brand. Also, when mixing together the ricotta and mascarpone cheese, DO NOT over mix it. If mascarpone cheese is over mixed, it becomes very thin.