Bittersweet Chocolate Cake
["8 oz. bittersweet or semi-sweet chocolate chips", "10 Tbsp. unsalted butter, cut into pieces", "4 large eggs, separated", "2/3 c. sugar", "3 1/2 Tbsp. flour"]
["Heat oven to 325\u00b0.", "Line 9-inch pan with waxed paper.", "Butter sides and paper; dust with flour.", "Melt chocolate in double boiler over simmering water, stirring until smooth.", "Cool slightly. Whisk yolks and sugar in bowl until pale yellow.", "Beat whites until stiff but not dry.", "Fold into chocolate mixture.", "Pour batter in pan.", "Bake about 25 minutes until toothpick comes out with only a few moist crumbs.", "Cool completely.", "Run knife around side.", "Turn onto platter and cool."]
["bittersweet", "unsalted butter", "eggs", "sugar", "flour"]