Place a doubled over cheese cloth into a strainer and place the strainer over a bowl to catch the drippings. Add the ricotta cheese to the cheese cloth, and bring the edges of the cloth together to cover the cheese. Let it drain for a couple of hours in the refrigerator. (You can also do it overnight.)
Preheat the oven to 325° and grease a 9 inch springform pan.You will need a large roasting pan that’s bigger and longer than the springform pan. (You can even use the aluminum foil disposable ones).If you are not sure about your springform holding up in water, you can wrap the outside of the springform pan in heavy duty aluminum foil from bottom up to the sides. Try to use a wide kind of foil so you would only need to use 1 solid sheet. (I recommend wrapping the outside of the springform in foil before adding the crust and cheesecake batter.)Although, there is a chance that a small amount of water will leak in, this will NOT ruin the cheesecake.
Pulse biscotti in a food processor until it turns to crumbs.
Combine the biscotti crumbs with melted butter and vanilla extract until thoroughly combined.
Spray inside of the springform pan with some cooking spray, making sure you get the sides too.
Spread biscotti mixture in the bottom of the prepared springform, evenly pressing it over the bottom and about half way up the sides.
Ricotta Cheesecake Filling:
In a bowl of an electric mixer, start beating mascarpone over high speed and gradually pour in the sugar. Beat a few more seconds until light and fluffy,.
Add in ricotta cheese, orange zest, vanilla extract, and Amaretto and beat until combined and smooth. Stop and scrape the bottom and sides of the pan.
On low speed, add flour and then bring the speed back up to medium-high. Beat in one egg at at time, letting each one incorporate before adding another. Make sure all ingredients are well incorporated and batter is nice and smooth.
Transfer the batter into the prepared springform and spread in evenly.
Baking the Cheesecake:
Preheat oven to 325°.Place a large roasting pan into the oven and place cheesecake springform inside the roasting pan. Carefully add hot water to the roasting pan, about half way up the side of the springform.
Bake for 85 minutes. Turn off the oven and open the oven door half way. Let cheesecake rest for 10-30 minutes in the oven. (You can gently touch the center of the cheesecake to make sure it's sprigs back up and not too squishy. If it ripples out, then the center is not cooked through.)
Take it out of the oven. Take the foil wrap off the pan and cool for an hour on the counter.
Cover the pan with air-tight wrap and refrigerate for about 6 hours or overnight before serving.
Before taking it out of the springform, make sure to rub a greased butter knife along the edge of the cheesecake to separate it from the pan.
You can decorate the cheesecake with fresh berries and powdered sugar.