Make the pasta dough: In a food processor, add the flour and semolina. With the motor running on low, slowly add the eggs until a dough forms. Wrap in clingfilm and refrigerate for 30 minutes to rest.
Prepare the filling: In a bowl, mix together the pumpkin purée and mascarpone. Season with salt and pepper, then stir in the crushed amaretti. Finish with a squeeze of lemon juice and mix again.
Roll the pasta:Using a pasta machine, roll the dough to its thinnest setting. Lightly dust a surface with semolina, and cut out 7cm rounds using a cookie cutter or glass.
Fill and seal: Place a spoonful of filling onto half of the pasta circles - keep the edges clear. Brush the edges with water and top with another unfilled pasta circle. Press the edges together to seal well.
Make the sauce: In a saucepan, melt the butter over medium heat and cook until it turns nut brown. Add the lemon juice and remove from heat.
Cook the ravioli: Bring a large pot of salted water to a boil. Gently drop in the ravioli and cook for 1 minute. Drain carefully.
Serve:Plate the ravioli and spoon over the brown butter sauce. Top with fried sage leaves and a generous grating of Pecorino Romano.