Directions

1. Set aside ¾ – 1 cup blueberries and ¼ of lemon zest for decoration.  
2. Mix together blueberry jam, remaining blueberries, lemon juice and remaining zest. 
3. Using an electric stand mixer with whisk attachment, whip heavy cream for about 3 minutes, until medium-stiff peaks form. Remove and set aside in a separate bowl. 
4. Add mascarpone, sugar, cinnamon, vanilla and salt to mixing bowl. Whip about 2 minutes until smooth, scraping bowl down once halfway through. 
5. Using a rubber spatula, fold 1/3 of the whipped cream into the mascarpone filling until completely combined. 
6. Gently fold in the rest of the whipped cream, making sure not to deflate it. Reserve about 1 cup of mascarpone filling in the refrigerator in an airtight container until cake is ready to serve. 
7. Line 9” square baking dish with two pieces parchment paper to make a sling to remove finished cake, leaving some overhang to pull up on and release cake once chilled. Line the entire bottom of prepared baking dish with one layer graham crackers, cutting as needed to fit in snugly. 
8. Spread half of remaining mascarpone filling evenly on top of graham crackers, followed by half of the blueberry mixture. Place another layer of graham crackers on top. 
9. Repeat the process with one more layer mascarpone filling, then blueberry mixture and then another layer graham crackers. 
10. Cover dish and refrigerator 8-12 hours. Transfer dish to freezer for 1 hour before serving.  
11. When ready to serve, run a hot knife around cake edges to release it from the baking dish. Carefully lift cake from the pan and put on serving plate. Spread reserved mascarpone filling on top layer and decorate with reserved fresh blueberries and lemon zest. 
12. Let cake sit about 10 minutes to soften before slicing/serving.