Start by preheating oven to 350 degrees F. Spray a 8 x 8-inch baking pan with no-stick spray, line with parchment paper, and set aside.
Prepare the cookie dough: using a stand mixer with a paddle attachment, combine butter and sugars, mixing just until creamy.
Add molasses, egg, flour, spices, 1 tsp vanilla, and baking soda. Beat the mixture on medium speed until homogeneous.
Spread half of the batter in an even layer in the prepared pan, using your hands if necessary; reserve.
Meanwhile prepare the dulce de leche filling. In a medium microwave safe bowl, melt caramel until mostly smooth.
Stir in 1/2 cup of sweetened condensed milk until obtaining a homogeneous mixture. Pour dulce de leche filling on top of the cookie batter, spreading gently in an even layer.
Then, drop flattened pieces of the remaining cookie batter on top of the filling until they mostly cover the dulce de leche filling.
Bake for about 20-23 minutes, transfer pan to a rack, and let cool for 10-15 minutes before topping with chocolate ganache.
While cooling, make the ganache. Mix remaining sweetened condensed milk with chocolate chips in another microwave safe bowl and heat for about 90 seconds.
Stir in until chocolate is melted and ganache is smooth and has thickened. Mix in 1/2 teaspoon of vanilla and spread over the baked cookie batter.
Let set in the refrigerator for at least 30-50 minutes, cut into squares, and decorate as desired. Enjoy with a cup of hot chocolate!