Heat oven to 350 degrees F. Coat inside of 1-1/2-quart souffle dish with nonstick cooking spray.

Separate eggs; place yolks in small bowl, whites in large bowl along with the 3 additional whites.

Combine cocoa powder, sugar, flour and salt in medium-size saucepan. Gradually whisk in milk until well blended. Cook over medium heat, whisking, until mixture thickens and boils, 10 to 12 minutes. Remove from heat. Add vanilla. Whisk a little hot chocolate mixture into yolks; whisk yolk mixture into chocolate in saucepan. Stir in chips until melted.

Beat together egg whites and cream of tartar at high speed until stiff, but not dry, peaks form.

Gently but thoroughly fold chocolate-yolk mixture into whites. Pour into prepared dish.

Bake in 350 degrees F oven for 35 minutes or until souffle is puffy and shakes slightly when jiggled.

While souffle is baking, press raspberries and syrup through fine sieve over bowl to remove seeds; you should have 1/2 cup sauce.

Serve souffle immediately with raspberry sauce. Garnish with fresh raspberries, if desired.