Marble Cheesecake

I wish I had a picture to go with this recipe.  This is an easy to make cheesecake that is absolutely excellent.  It's always a favorite around here.
1 c graham cracker crumbs
3 Tbsp. sugar
3 Tbsp. butter, melted
3 8-oz. pkg. cream cheese
3/4 c sugar
1 tsp vanilla
3 eggs
1 1-oz. square unsweetened chocolate, melted

Combine crumbs, sugar and butter.  Press onto bottom of 9" cheesecake pan.  Bake at 350 for 10 minutes.  Set aside.

Combine cream cheese, sugar and vanilla, mixing at medium speed.  Add eggs, one at a time, mixing well.  Blend chocolate into one cup of the batter.  Spoon plain and chocolate batter over the crust, alternately.  Swirl batter in pan with a knife several times for marble effect. 

Bake at 450 for 10 minutes.
Reduce over temperature to 250 and bake for 30 more minutes.  Loosen cake from rim of pan.  Chill.