Heat the oven to 350 degrees.

Cut the squash in half lengthwise and scoop out the seeds. Note: Acorn squash is very hard, so take care when cutting it in half. We set each squash on a cutting board, wedged a knife in slightly, then carefully pressed down on both ends of the knife. Cut each half in half again so you have 8 pieces.

Arrange the squash in a 9- by 12-inch baking dish skin-side up and add 1/2 cup of water. Cover tightly with foil and bake until the squash can be easily pierced with a knife or carving fork, 45 to 50 minutes.

While the squash is roasting, pulse together the butter and the hazelnuts in a food processor to make a rough paste, almost like a soft cookie dough. Add the liqueur and pulse again to mix it in.

When the squash is soft, remove it from the oven and increase the temperature to 450 degrees.

Drain the water from the baking dish and invert the squash so that it is skin-side down. Salt it lightly, then divide the hazelnut butter evenly among the squash pieces, spooning it into the cavity. It will take a bit more than a tablespoon per piece.

Return the squash to the oven and bake until the tops are lightly browned, about 15 minutes.

This recipe yields 8 servings.

Each serving: 138 calories; 98 mg. sodium; 16 mg. cholesterol; 10 grams fat; 4 grams saturated fat; 10 grams carbohydrates; 2 grams protein; 2.88 grams fiber.