For the dough: In a small saucepan, over high heat, bring the water and salt to a simmer. Put the flour in a medium bowl. Pour the hot water over the flour and stir with a rubber spatula or wooden spoon to bring it together into a shaggy dough. Transfer the mixture onto a lightly floured surface and continue to work and knead the dough until smooth, about 5 minutes. Allow to rest for at least 10 minutes at room temperature.
Meanwhile for the filling, in a medium bowl mix together the ricotta, caciotta, Parmigiano Reggiano, oregano, egg and salt.
For the sauce: Heat a medium saucepan over medium heat. Add the olive oil and garlic and cook, stirring, for 2 minutes until the garlic is lightly browned. Stir in the tomato puree and nestle in the basil and cheese rind. Add the salt. Simmer, stirring often, until the sauce is slightly thickened, about 12 minutes. Remove and discard the basil and cheese rind.
Bring a large pot of water to a boil. Season with salt.
On a lightly floured surface, roll the pasta dough into a large rectangle about 1/8-inch-thick. Place little mounds, about 2 teaspoons, of the filling about an inch apart down the edge of the rectangle closest to you. Fold the unfilled portion of the dough over the line of filling and gently press down around all the filling to seal the dough. Using a small 2 1/2-inch round cookie cutter or drinking glass, cut out the ravioli. Remove any scrap dough from the top and repeat the process. You should end up with around 30 ravioli. In batches, add the ravioli to the boiling water and simmer until they float and are cooked through, about 3 minutes. Remove with a spider or slotted spoon.
To serve, place a spoonful of sauce in the center of the plate and position the ravioli around it. Sprinkle with more Parmigiano Reggiano and garnish with a few leaves of basil.