Preheat oven to 425°F (220°C). Brush acorn squash with 2 tbsp (30 mL) oil. Sprinkle with garlic and 1/4 tsp (1 mL) each salt and pepper. Arrange in single layer on parchment paper-lined baking sheet; bake for 40 to 45 minutes or until golden brown and tender. Scoop out pulp, leaving 1/2-inch (1 cm) border. Reserve squash shells; set aside. Mash squash pulp until smooth.
Heat remaining oil in small skillet set over medium heat; cook sage leaves for 2 to 3 minutes or until crispy. Strain and reserve oil; set aside.
Meanwhile, cook pasta according to package directions. Drain, reserving 1 cup (250 mL) cooking liquid. Toss together pasta, reserved cooking liquid, mashed squash, lemon zest, and remaining salt and pepper. Toss with Parmesan and walnuts.
Divide pasta mixture among reserved squash bowls. Top with dollop of ricotta and crispy sage leaves. Brush reserved sage oil over baguette toasts; serve with pasta.
Add cooked and crumbled Italian sausages for protein.To toast baguette slices, arrange in single layer on baking sheet. Broil for 1 to 2 minutes per side or until golden brown and toasted.