Pumpkin Chocolate Chip Snack Cake

0 Preheat oven to 350 degrees F.
1 Line an 8 x 8 baking dish with parchment paper and / or spray it with nonstick cooking spray.
2 Whisk together egg and egg yolk. Set them near the oven as it's heating up (the eggs should be about room temperature when you add them to the batter).
3 In a small bowl, whisk together flour, pumpkin pie spice, cinnamon, baking soda and salt.
4 In the bowl of a standing mixer or with a hand mixer, beat butter until creamy. Add granulated sugar and brown sugar and beat on high until light and fluffy, ~2 minutes.
5 Add egg, egg yolk and vanilla and mix until combined.
6 Add pumpkin puree and mix on medium until combined (the mixture will look lumpy and slightly broken).
7 Add dry ingredients in two increments, mixing on low between each addition. Add 2/3 cup chocolate chips and stir to combine.
8 Pour batter into prepared pan and smooth the surface out with a spatula (it will be quite thick). Sprinkle a few chocolate chips over top.
9 Bake until the cake is just set in the middle, 30-35 minutes (see note).
10 Let cool completely in the pan before slicing into squares.