Make the Crust

1. Preheat oven to 350˚F. Grease a 9-inch springform pan. Cover the sides with foil to protect against the water bath used to cook the cheesecake.
2. In a medium bowl, combine crushed graham crackers, sugar, butter, and cinnamon together until thoroughly mixed.
3. Using a flat-bottomed surface, press the graham cracker mixture onto the bottom of the pan.
4. Place the pan on a middle rack in the preheated oven and bake for 10 minutes. Remove and set aside to cool. Lower the heat to 325˚F.

Make the Filling

1. Using the paddle attachment of a stand mixer or a hand mixer and a large mixing bowl, add the cream cheese and mascarpone cheese. Mix on a medium speed until smooth.
2. Add the sugar slowly and mix until smooth.
3. Add the vanilla extract, lime juice, lime zest, and salt and mix until smooth.
4. On a slow speed, add the eggs one at a time, mixing until just combined.
5. Slowly pour the filling mixture on top of the cooled crust.
6. Place the foil covered spring form pan in a roasting pan and put on the middle rack in the oven. Fill with water half way up the pan.
7. Bake for 60 to 75 minutes, until edges are set and the center of the cheesecake is still slightly jiggly.
8. Leaving the cheesecake in the oven, turn off the heat and pop the oven door open an inch for another 60 minutes, to let the cheesecake cool down slowly (and reduce the chance of cracking if you're going to serve this as a whole cheesecake).
9. Take the cheesecake out of the roasting pan and chill in the fridge overnight.
10. To remove the cheesecake from the pan, run a paring knife around the sides. Open the pan and remove the ring.*

Assemble the Trifle

1. Make the key lime whipped cream: In a large mixing bowl, whisk heavy whipping cream, powdered sugar, and vanilla paste or extract, and lime zest.*
2. In a trifle bowl or "tasting" trifle bowls, or just a glass serving bowl or even just glasses (I used my glass coffee mugs 😂),  sprinkle a thin layer of graham cracker crumbs.
3. Follow with a layer of cheesecake + crust (I used a cookie scoop). Spread with a layer of the whipped cream. Repeat as desired until your trifle serving dish(es) is(are) full.
4. Top with remaining key lime whipped cream. Garnish with a few key lime slices and a sprinkle of lime zest and graham cracker crumbs. Store in the fridge until ready to serve.