Pumpkin and Walnut Ravioli

FOR RAVIOLI: Place pumpkin in medium bowl. Whisk in ground walnuts and ricotta to blend well. Season to taste with salt. Whisk egg into pumpkin mixture to blend.

Sprinkle two baking sheets with semolina. Follow method for making Fresh Pasta and forming 4- to 5-inch wide pasta sheets; do not dry pasta. Working with one pasta sheet at a time, lay sheet on work surface (cover remaining sheets with damp kitchen towel to keep moist). Spoon generous teaspoonfuls pumpkin mixture on lower half of pasta sheet, spacing mounds 3/4-inch apart. Fold top half of pasta sheet over filling so the edges can meet. Press between mounds of filling so dough sticks together, removing as much air as possible between layers. Press edges together firmly.

Using pasta cutter, cut between mounds to form ravioli; trim any uneven edges. If dough is too dry, brush edges and between mounds of filling very lightly with water before folding dough over filling to help dough stick together. Transfer ravioli to prepared baking sheets. Repeat with remaining pasta sheets and pumpkin filling. Let ravioli rest 15 minutes.

MEANWHILE, PREPARE SAUCE: Melt butter and creme fraiche in heavy small saucepan, over low heat. Whisk together; add sage. Keep warm over very low heat.

TO SERVE: Working in batches, cook ravioli in large pot of boiling salted water until ravioli float to surface and are tender but still firm to bite, about 3 minutes. Drain. Transfer ten ravioli to each of six warm pasta bowls. Spoon sauce over ravioli. Sprinkle with finely chopped walnuts and serve.