Edison's Chocolate Chip Cookie Cake

Adapted from Life is But a Dish.

PREP: 30 min
SERVES: 8

INGREDIENTS
10 Tbsp unsalted butter, at room temperature
2/3 cup brown sugar
1/3 cup white sugar
1 egg, plus 1 egg yolk
1 tsp vanilla extract
1 2/3 cup all-purpose flour
3/4 tsp baking soda
3/4 tsp salt (*NOTE: I think this is way too much salt--reduce to 1/2 tsp next time.)
1 cup chocolate chips, divided

DIRECTIONS
1. Preheat oven to 350 degrees and grease a 9" cake pan. Set aside.
2. Using a stand mixer or hand mixer, cream the butter, brown sugar and white sugar together for 2 minutes and then blend in the egg, egg yolk, and vanilla.
3. Add the flour, baking soda and salt and mix until combined. Use a wooden spoon or spatula to mix in all but 2 Tbsp of chocolate chips.
4. Press the cookie dough into the cake pan until evenly distributed. If using your hands, wet your hands lightly so the batter doesn't stick. Sprinkle the remaining 2 Tbsp of chocolate chips on top and press them down slightly.
5. Bake for 22-25 minutes until the top is golden brown. Let the cookie cool completely and then run a knife along the edge to loosen. Transfer to a platter. Pipe on frosting along the edges and add the sprinkles. If you don't want to pipe frosting you can simply spread on top.