Cook sausages according to package instructions and allow to cool completely.
While the sausages are cooking, place the 00 flour in a large mixing bowl, making a well in the center.
Add 3 whole eggs, 1 yolk, and 1 tablespoon of extra virgin olive oil into the well. Using a fork, whisk together the eggs and olive oil, incorporating some of the flour as you go.
Combine the remaining flour with the egg mixture until a rough dough is formed.
Dust the work surface with some of the semolina flour. Turn the dough out onto the surface and knead for about 10 minutes, or until the dough is smooth and pliable.
Wrap dough in plastic wrap and refrigerate for about 30 minutes.
While the dough is resting, combine the cheeses, remaining egg, and sage in a mixing bowl.
Transfer the mixture to a fine-mesh sieve over the sink or another bowl and allow to drain for about 30 minutes.
While the filling is draining, remove the pasta dough from the refrigerator, divide into two balls, and cover one of them.
Pass the first ball through a pasta roller, decreasing by one notch each time, dusting with semolina each time, until you get to the second-to-last setting.
Place 1½ tablespoons of the filling on the bottom half of the dough sheet and fold over the top half to cover.
Tamp down the pasta around the filling with a small glass (a champagne flute works well), then press the dough around the filling to seal.
Use a pasta cutter to cut evenly between each ravioli and transfer to a lined sheet tray dusted with semolina.
Repeat the entire process with the remaining dough ball and filling.
Bring a large pot of water to a boil.
Slice the sausages on an angle into 4 slices.
Heat a large pan over medium-high heat.
Add the remaining olive oil to the pan and add the garlic and sausage slices
When the garlic is just beginning to get some color, add the crushed tomatoes and basil, reduce heat, and simmer for about 5 minutes
Drop the ravioli into the boiling water in batches to avoid crowding the pot. When they float to the top of the water, remove with a slotted spoon to a sheet tray.
When all of the ravioli are done, place them on a large serving platter and top with the sausages and tomato sauce.