Cut squash in half lengthwise; remove and discard seeds and membranes. Place squash halves, cut side down, in a 13- x 9-inch baking dish. Add water to depth of 1 inch.
Bake, covered, at 375° for 30 to 40 minutes. Let cool; scoop out pulp, and mash.
Beat pulp, egg yolks, whipping cream, and next 5 ingredients at medium speed with an electric mixer until blended. Set mixture aside.
Beat egg whites at high speed until stiff peaks form; gently fold into squash mixture. Spoon into a lightly greased 2-quart souffle dish. Sprinkle with almonds.
Bake at 350° for 55 minutes or until puffed and golden. Serve immediately.