Preheat oven to 375°. Line 8x8 glass baking dish with parchment paper, ensuring that the paper slightly hangs over the edges of the dish. In a large mixing bowl, combine all ingredients for cookie, except morsels and nuts. Gently fold in the morsels and nuts. Using a greased spatula, evenly spread half of the dough mixture into the dish. Bake for 15-20 minutes or until dough is fully cooked. Lift dough out of dish by the edges of the parchment paper and allow to cool on cooling rack. Place parchment paper back in dish and add the second half of dough. Cook following above instructions. Set cookies aside while cooling.

In a large mixing bowl, thoroughly mix all ingredients for cream filling. Cover bowl and place in freezer for 10 minutes. Line 8x8 glass baking dish with new piece of parchment paper and allow paper to slightly hang over edges. Place one of the cookies in the dish with the bottom facing up. Using spatula, evenly spread cream filling on top of cookie. Place second cookie, bottom-side down, on top of filling. Cover dish and place in freezer for at least 2 hours. Cut into squares before serving.