Wash the guavas and separate the seeds from the flesh, make sure there are no seeds left behind as they will remain very hard even after cooking and biting into one may even chip a tooth. Reserve the flesh.
Mix the seeds with a 1 ½ quart [1.5 lt] of water and the sugar. Simmer over low heat until the liquid has reduced to a third.
Sieve to remove the seeds. Add the guava flesh to the liquid. Simmer over low heat until the liquid has further reduced to half. Remove from the heat and cool to room temperature.
Mix in a blender until there are no clumps. Return to the heat and simmer stirring over low heat until it becomes very thick.
Remove from the heat and reserve.
Place chilled butter and graham crackers in the food processor and pulse until it resembles coarse brown sugar.
Pour into a 9" [23.5 cm] pie pan. Press on the bottom and sides to form the crust. Chill in the fridge for an hour.
Ricotta filling and assembly
Heat oven to 300 ºF [150 ºC]
Open the pod lengthwise and scrape out the seeds with a paring knife.
Mix ricotta, vanilla seeds and condensed milk in the mixer (use paddle attachment).
Add eggs and mix thoroughly.
Pour the ricotta mix into the chilled crust.
Bake for 30 minutes. Remove from the oven and cover with the guava jam.