Preheat oven to 350°F, then spray 9 x 5 bread pan with nonstick spray
Make the cinnamon swirl by combining 1 tbs of cinnamon and 1/3 cup of granulated sugar mixing together in a small bowl , then set aside
Whisk the flour, baking soda, and salt together in a large bowl. Stir in the chocolate chips. Set aside
In a medium bowl, whisk the egg, brown sugar, and granulated sugar until product is smooth
Whisk in the buttermilk, oil, and vanilla. Slowly pour the wet ingredients into the dry ingredients and gently whisk until there are no more lumps. Avoid over-mixing.
Spread half of the batter into prepared loaf pan. Top evenly with 3/4 of your cinnamon-sugar mixture
Gently spread the remaining batter on top as best you can and sprinkle the rest of the cinnamon-sugar
Sprinkle with a couple more chocolate chips if desired. After use a toothpick to create more of a swirl
Bake the bread for 50-60 minutes, tenting loosely with aluminum foil halfway through baking. Use a toothpick to check doneness
Let bread cool on a rack for 30 minutes then enjoy