Pumpkin Chocolate Cheesecake Squares

I baked pumpkin-chocolate cheesecake for National Cheesecake Day a couple of weeks ago. Not only did I hear of this holiday the first time, but also the style of the cheesecake. No matte of what, it turned out good. And I guess from this year I will celebrate the cheesecake day anually...

1 recipe Graham cracker crust
2  8-ounce cream cheese, softened
1& 3/4 cups sugar
3 eggs
1 cup canned pumpkin
1/2 tsp pumpkin pie spice
1/2 tsp vanilla
1/4 tsp salt
6 ounces (1 cup) semisweet chocolate chips
2 tbsp butter

    Preheat oven to 325 degress. Prepare graham cracker crust. In a large bowl mix cream cheese and sugar with an electric mixer on medium speed until smooth. Add eggs, one at a time. Beat in pumpkin, spice, vanilla and salt on low speed until combined. Pour 1&1/4 cups of the pumpkin mixture into another bowl.
    In a saucepan heat chocolate and butter until melted, stirring. Whisk the chocolate mixture into the 1&1/4 cups of pumpkin mixture. Spread the mixture evenly over the crust.
    Bake for 15 minutes, remove from oven. Pour remaining pumpkin mixture over chocolate layer. Bake for 40-45 minutes. Cool completely. Cover and chill for 3 to 24 hours before cutting. Cut into desired-size squares.
    You can also try spreading sour cream over the cake when serving. I tried that, and it was pretty good.
    Graham Cracker Crust: Lightly grease a 13*9*2-inch baking pan. In a bowl combine 1&1/4 cups graham cracker crumbs and 1/4 cup sugar. Add 1/3 cup melted butter, mix well. Press crumb mixture evenly over bottom of the pan.