I don't know where you are in South America, but in Brazil they have that specific cereal that you are looking for.
It's called "flocos de arroz" from Kellogs. They have also "Choco Krisps" which...
For the cannelloni or lazagne I make the dough:
1 3/4 cups all-purpose flour or more
3 eggs, room temperature
1/4 tsp salt
1/2 tsp olive oil
2 cups ricotta cheese
1 cup shredded mozzarella