DRAIN RICOTTA: Measure out the ricotta and place it on top of several paper towels. Press down with a few more paper towels to remove excess moisture. Alternatively, add ricotta to a cheesecloth and squeeze out excess moisture over the sink.
BEAT: Combine ricotta cheese, mascarpone cheese (drain off any liquid if there is any on top), vanilla extract, powdered sugar, and salt into a large mixing bowl fitted to a stand mixer with a paddle attachment (or add to a large bowl and use a hand mixer). Beat on medium-high speed until the dip is thick and creamy, about 5 minutes. Scrape down the sides of the bowl as needed.
CHILL: Use a spatula to gently fold in chocolate chips. Transfer to an airtight container and let chill for 30 minutes or up to an hour.
SERVE: Remove dip from the fridge and give it a quick stir. Transfer to serving platter and surround with dippers of choice!
STORAGE: This dip will last nicely in the fridge for 3-4 days in an airtight container. Note that as it sits in the fridge, it does begin to collect a bit of liquid after the first day. This isn't a big deal; drain it off and give it a good stir before serving again! Because of the dairy in this dip, it isn't a great candidate for freezing and thawing as it will likely separate and become grainy.
Note 1: Mascarpone cheese: This dip is the absolute best with mascarpone, but full-fat, brick-style cream cheese will work in a pinch (you may want a touch more sugar). Mascarpone cheese is richer, creamier, and more flavorful in this dip so try to use it if possible. It can be found usually in one of three places in the grocery store: the deli counter, in the dairy section (near the cream cheese or sour cream), or in the specialty foods section (near fancier cheeses like brie).Note 2: Ricotta cheese: Pick whole milk, high-quality ricotta cheese -- this way you won't need to strain off too much excess liquid. Better ricotta has a richer flavor in this dip. Low-fat ricotta won't whip up to a thick and creamy dip.Note 3: Dippers: We like crunchy chocolate chip cookies and butter waffle cookies best! Here are some more ideas: