Set aside ½ cup of the sweetened condensed milk. Pour the rest over the top of the cake.
Cover and refrigerate for ~1 hour or until milk is absorbed.
In a large bowl combine ricotta cheese, mascarpone cheese, cinnamon, and vanilla extract. Mix under smooth.
Add powdered sugar a little at a time until just combined.
Mix in remaining sweetened condensed milk.
Spread frosting evenly over cake.
Sprinkle with mini chocolate chips and dust with additional powdered sugar if desired.
Refrigerate for 2-3 hours before serving. Store in the refrigerator.
Ingredient Notes and Shopping Tips
Ricotta Cheese: Ricotta is a traditional Italian cheese that has a mild flavor. It's most commonly made from water, salt, and whole milk that is separated into curds and whey. The curds are then cooked in whey, producing a creamy white solid. It is often used in savory cooking such as lasagna. Grab the whole milk variety if you can. Also, don't substitute cottage cheese for the ricotta in this recipe. It is cheaper but will not give you the same rich flavor or texture. Look for it in the dairy section near the sour cream.
Marscapone Cheese: Mascarpone is a fresh, mild Italian cheese. It has a soft, creamy texture and pale yellow color. The name comes from the fact that it's made from milk which has been treated to have a higher content of butterfat - this gives it its unique texture. The creaminess of the cheese makes for the perfect filling for cannoli or other desserts. You can vary the sweetness by adding honey or sugar to taste. If you cannot find it, you can use cream cheese but it won't be quite as good. Look for it near the specialty cheeses in the deli (mine is near the wedges or parmesan).
Sweetened Condensed Milk: Be sure to use sweetened condensed milk and not evaporated milk. Both have water removed, but the sweetened version has sugar added. Look for it in the baking aisle near the cake mixes.
Chocolate Chips: These are my topping of choice! However, others such as pistachios or even chopped cannoli shells (or waffle cones) would be tasty.
Line your pan with nonstick foil sprayed with cooking spray for easy cleanup and removal.
Doneness: Cake is done when a toothpick inserted in the center comes out clean or with just a few moist crumbs. If you see raw batter, continue baking for 2-3 minutes at a time. A fully cooked cake will also spring back when touched.
Poking Holes: Poke holes using the back of a wooden spoon. Aim for 1-2 inches apart to make sure you get some filling in every bite.
Be Patient: Don't skip chilling the cake as it needs time to set up. Never add frosting like this to a warm cake as it will slide right off.