Butternut ravioli with sage butter

1 butternut squash
4 teaspoons extra-virgin olive oil
2 teaspoons light-brown sugar
1 large egg
1 dash amaretto
2 tablespoons ricotta cheese
1 teaspoon shallots, chopped
Pinch of nutmeg
Coarse salt and freshly ground pepper
1 package of (20+) wonton wrappers
1 tablespoon semolina flour
1/2 cup (1 stick) unsalted butter
1 tablespoon freshly chopped sage leaves
a few whole sage leaves for garnish
2 tablespoons balsamic vinegar