In a separate large bowl, whisk together pumpkin, sugar, butter, eggs and vanilla. .
15 oz pumpkin puree, 1 cup granulated sugar, 1/2 cup butter, 2 large eggs, 1 teaspoon vanilla extract
Add the wet ingredients to the dry ingredients and stir until the flour starts to incorporated, but it not combined. Add 3/4 cup of chocolate chips and mix until it is just combined, be careful not to over mix.
1 cups chocolate chips
Pour into prepared pan and top with the remaining chocolate chips. Bake for 55-65 minutes, or until a tester comes out clean.
Remove from oven and cool for 10 minutes before removing from the pan to cool completely.