Preheat the oven to 350 degrees and grease a 13″ x 9″ pan.

Melt the butter and the chocolate chips together in a saucepan and set aside to cool for 15 minutes. 

Add the eggs, sugar, and vanilla  to the mixture in the saucepan, and mix until smooth. Sift the flour and baking soda together in a separate bowl and add to the chocolate mixture. Combine until it’s a smooth batter.

Pour mixture into the greased pan and spread across the whole pan evenly. Place in the preheated oven for 15 – 20 minutes, remove, and let cool. The edges of the brownie might have risen, with a sharp knife, cut those edges down so that the brownie is completely level. 

Place about one inch of water in a saucepan and let it come to a slow simmer.

In a glass or metal bowl, combine all the ingredients for the fudge. Place the bowl on top of the simmering water and fold the ingredients with a spatula until it’s completely melted together. This shouldn’t be rushed and should take around 15 minutes to completely melt.

Pour the fudge over the brownies. The brownies can still be warm but not hot. Smooth with the back of a spoon and make swirls. Place in the fridge for 1-2 hours to set.

Sprinkle brownies with flaked sea salt and cinnamon. Slide the warm knife around the outside edge of the brownies. With a warm knife, cut into small squares.