Combine the flour, semolina, yeast and salt. Mix in both oils and the melted butter, then start with 1 1/2 cups (340g) water. Knead until the dough is elastic and fairly stiff, adding more water as needed.

Cover in a greased bowl and let rise for 1 hour. For more flavor, the source allows refrigerating it afterward for several hours or up to 24 hours.

Divide the dough: about three-quarters for the bottom crusts and one-quarter for the top crusts. Divide each portion in half.

Butter two 9-inch round pans at least 2 inches deep. Add a little olive oil to the bottom of each.

Roll each larger dough piece into a 15- to 16-inch circle and each smaller piece into a 9- to 10-inch circle. Cover and let relax for 15 minutes.

Line each pan with a larger dough circle, allowing the edges to overhang. Divide the raw sausage between the pans in a thin, even layer. Add the mozzarella and spinach, if using.

Cover with the smaller dough circles. Fold and firmly seal the edges. Pierce the top crusts to let steam escape.

Cover and let rest for about 30 minutes. Preheat the oven to 425°F (about 220°C).

Divide the sauce over the top crusts and sprinkle with the grated cheese.

Bake on a lower oven rack for 40–45 minutes, until the crust is golden and the filling is bubbling. Check that the sausage reaches 160°F (71°C) in the center. If desired, move the pizzas to an upper rack near the end for additional browning.

Let rest for about 15 minutes. Carefully remove from the pans and cut into wedges. Finish with optional basil and serve with extra sauce for dipping.