Cup of Yum
1. Line 8 x 8 baking dish with parchment paper, leaving about a 1-inch overhang on all sides. Set aside.
2. In a bowl, combine heavy cream and condensed milk. Using a hand mixer on low speed, whip mixture until it reaches firm peaks. 
3. Gently fold in half of the diced mangoes, making sure not to deflate the whipped cream. 
4. Arrange one layer of graham crackers on bottom of prepared dish. Spoon ⅓ of cream mixture on crackers and spread to cover.
5. Arrange another layer of graham over the cream. Spoon and spread ⅓ of the cream mixture. Repeat with another layer of graham crackers. Spoon and spread remaining ⅓ of the cream mixture on top of crackers. 
6. Arrange the remaining diced mangoes on top of the cream and garnish with crushed graham crackers.
7. Cover tightly with plastic film and freeze for about 4 to 5 hours until firm.
8. To serve, lift the cake from the pan using parchment paper overhang as support and transfer onto a serving platter. Cut into serving portions.

If Using Mango Puree

Cup of Yum
1. In a saucepan over medium heat, combine mangoes and sugar.
2. Bring to a boil, stirring occasionally, until sugar is dissolved and the mixture is very thick. 
3. Transfer to a bowl and allow to cool completely. 
4. Gently fold mango puree into the whipped cream, making sure not to deflate.
5. Use the cream mixture in assembling the cake.