Brown your butter by heating your sauce pan over medium high heat and adding your butter to the pan. Constantly swirl or stir your pan until it begins to bubble constantly. Keep swirling and look for the bottom of the pan to start to darken and the smell to turn nutty and warm. Pull off the heat when it turns the color of cinnamon and then set aside in a bowl to cool down while preparing your other ingredients.
In one mixing bowl, add your mashed bananas, eggs, sugar, molasses, salt, vanilla, and skyr. Mix until completely combined. Add your browned butter to the bowl and stir to combine.
In a separate mixing bowl, add your AP flour, rye flour, baking soda, and cinnamon then whisk together, making sure to incorporate the bottom and sides for a thorough mix.
Add your dry ingredients to the wet ingredients and use a silicone spatula to mostly mix. Then add your chocolate and stir until completely combined.
Cut your parchment paper to fit across the long sides of your loaf pan. Grease your loaf pan and then press the parchment into the sides to give yourself handles for the loaf when done.
Add your batter to the pan, then tap your pan on the counter to even out the top. Sprinkle with sugar to cover the top, then sprinkle finishing salt on top.
Put your loaf pan in the oven and cook for 60-70 minutes, or until a cake tester comes out clean.
Remove from the pan and rest on the cooling rack until cool enough to cut. Enjoy!
