Preheat oven to 350°F. Grease and line a 9" springform pan with parchment paper, set aside.
For the Gingerbread Cookie Cake
In a large bowl, cream butter and brown sugar together until light and fluffy. Beat in egg, egg yolk, vanilla and molasses until smooth. Add spices, baking soda and flour and mix until just combined. Dough will be sticky.
Press dough down into prepared pan. Using a rubber spatula or piece of foil sprayed with cooking spray will keep the dough from sticking so it's much easier to spread.
Bake for 22-25 minutes or until the top does't look "wet" anymore. Cookie cake will seem underdone when you take it out, but that is what keeps it so soft and chewy when it sets.
Once done, place pan on wire rack and remove the outer ring. Allow it to cool completely before frosting. If the center sinks down a bit, press down gently on the edges to even it out while still warm.
For the Cream Cheese Frosting
Cream together the cream cheese and butter until completely smooth. Add in the vanilla. Incorporate the powdered sugar one cup at a time until light and fluffy.
Once the cookie cake is completely cool, you're ready to frost. To frost as seen here, warm 2-4 tablespoons of the frosting and drizzle over top of the cookie cake. Pipe the rest of the frosting around the edges and garnish with sprinkles.
Storage instructions: This Gingerbread Cookie Cake will stay soft and fresh for up to 5 days stored in an airtight container at room temperature.