In a medium bowl, add 2 cups cream and 6 tablespoons sugar and whisk, using a hand mixer, until soft peaks form, 3 to 4 minutes. Slowly add the cream cheese and beat until fully incorporated.
Spread 1 1/2 cups cream cheese mixture on the bottom of a springform pan and arrange a layer of graham crackers on top. Spread another 1 1/2 cups cream cheese mixture and one more layer of graham crackers. Spread the remaining cream cheese mixture on top, making sure you have a smooth top. Cover the pan with plastic wrap, making sure it touches the top layer, and freeze until firm, about 2 hours.
Remove from the freezer and place in the refrigerator for about 6 hours to defrost but still remain firm.
Place the remaining graham crackers in a food processor and grind until you have fine crumbs. Using your hand mixer, whip the remaining 1 cup cream until stiff peaks form and add the cinnamon and the remaining 3 tablespoons sugar.
Remove the plastic wrap and the side of the pan and frost the cake all over with the cinnamon cream. Sprinkle the whole top of the cake with graham cracker crumbs. Serve cold.
What Really Makes This Recipe Sing: This is a wonderful cake to serve while entertaining in the summer. Your guests will be amazed at this. And to think, you didn't even have to turn your oven on.
BYOC: Melt your favorite farmer's market berry preserve and serve as a sauce. If you can't fine chocolate graham crackers, try using chocolate wafers.