Thin mint cheesecake

1 10 oz pkg thin mint cookies crushed and divided
1/4 c butter melted
4 8 oz cream cheese softened
1 8 oz container sour cream
1 c sugar
1 t vanilla extract
4 eggs
1/2 c chocolate chips

Preheat oven to 325
Line bottom and sides of a 9 inch springform pan with aluminum foil allowing 2 -3 inches to extend over sides
Stir together 1 /2 cups cookie crumbs and butter
Press firmly onto pottom of prepared pan
Beat cream cheese at medium speed with an electric mixer until smooth
Add sour cream, sugar, and vanilla beating well
Add eggs 1 at a time
Beating at low speed just until blended after each addition
Pour into prepared crust
Microwave chocolate chips in microwave safe glass bowl at high 1 2/ minues or until smooth
stirring at 30 sec intervals
Pour melted chocolate onto cener of cheescake batter
Swirl chocolate into batter using small spatula
Don't over stir
Bake 325 for 1 hour and 10 min
or until cener is almost set
Cool on a wire race 1 hour
Cover and chill at least 8 ohours
Gently run a knife around outer edge of cheesecake to loosen remove sides of pan and foil
Let stand for 30 minutes before serving
Sprinkle with remaining cookie crumbs