Preheat oven to 350 degrees and spray a 9x5 loaf pan with pam baking spray
Using a medium bowl, whisk together the flour, sugar, baking soda, baking powder, kosher salt, and the cinnamon.
Using a large bowl, whisk together the buttermilk, canola oil, vanilla and eggs until combined.
Gradually beat in the dry ingredients until combined.
Using a small bowl, whisk together the melted butter and 1 1/2 tbsp ground cinnamon until combined.
Pour half of the bread batter into the loaf pan.
Pour half of the cinnamon butter mixture onto the batter.
Using a knife, swirl the cinnamon butter mixture into the batter.
Top with the remaining batter.
Swirl the rest of the cinnamon butter mixture into the batter.
Place the bread pan onto a cookie sheet and place into the preheated oven and bake for 50-60 minutes or until a knife comes out clean.
Allow cooling for 10 minutes before removing and placing onto a wire rack.