reese's peanut butter cookie cake

the goods:

1/2 cup butter, softened
3/4 cup brown sugar, packed
1/4 cup sugar
3/4 cup creamy peanut butter
1 egg
1 teaspoon vanilla extract
1 and 3/4 cups flour
3/4 teaspoon baking soda
12 ounce bag of Reese's miniature peanut butter cups, chopped
3/4 cup semi-sweet chocolate chunks
chocolate sauce (optional)

In the bowl of an electric mixer, cream together butter and sugars until light and fluffy, about 3-4 minutes, Mix in peanut butter, egg, and vanilla extract. Add flour and baking soda and stir to combine. Stir in chocolate chunks and 1/2 cup of the chopped Reese's.
Preheat oven to 350 degrees. Line a 9-inch cake pan with parchment paper and lightly grease pan sides and corner. Press dough evenly into the cake pan. Bake for 18-20 minutes. Remove from oven and cool 15-20 minutes in the pan. Carefully remove from pan and allow to cool completely. When cookie is cooled, drizzle lightly with chocolate sauce (I used some leftover ganache I had lying around) so peanut butter cups will stick. Then pile top with remaining peanut butter cups and drizzle with additional chocolate sauce if desired.