Butternut Squash, Ricotta, and Sage Crostini

INGREDIENTS

• 24 fresh sage leaves
• 1 2-pound butternut squash, peeled, seeded, cut into 1/2" cubes (about 4 cups)
• 1 1/2 teaspoons (packed) light brown sugar
• 3 1/2 tablespoons extra-virgin olive oil, divided, plus more for drizzling
• 1/2 teaspoon finely grated lemon zest
• Coarse sea salt and freshly ground black pepper
• 12 3/8"-thick baguette slices, toasted
• Fresh lemon juice
• 3/4 cup fresh ricotta