Preheat oven to 350 degrees.

Make chewy base by combining all ingredients, kneading until a dough forms. Cover and chill the dough for about 30 minutes.

Once dough is chilled, press into a greased casserole dish or brownie pan and poke with a fork. Bake for about 20 mins or until golden brown and firm, then set aside to cool.

Make caramel by melting all caramel ingredients together, stirring constantly. Bring to a boil, then reduce heat until simmering for about 5 minutes or until it is thick and a caramel color (make sure you stir the whole time or the bottom will burn, yuck!).

Pour the caramel over the cookie base, then chill in the fridge until cold.

Once cold, melt brown and white chocolates separately and spread into 4 alternating stripes (white, brown, white, brown) over the caramel mixture. Using a toothpick, make big, loopy swirls all throughout the chocolate.

Top with nuts or toffee if desired and let cool until in hardens. For easy cutting, run a large knife under hot water with every slice.