Preheat oven to 350°. Spray a 9 by 5-inch loaf pan with nonstick cooking spray.

In a large bowl combine the flour, brown sugar, 1/2 cup granulated sugar, baking soda and salt. In a glass measuring cup beat the buttermilk, egg and butter until combined then pour over the dry ingredients. Stir in 1/2 cup butterscotch chips until everything is just combined. Do not overmix.

In a small bowl, combine the cinnamon and remaining 1/2 cup granulated sugar.

Pour half of the batter into pan then sprinkle with half the cinnamon-sugar. Carefully spread with remaining batter and sprinkle with remaining cinnamon-sugar. Cut through batter with a knife or skewer to swirl.

Bake for 45 to 50 minutes, or until a toothpick inserted into the center comes out clean. Let cool 10 minutes before removing from the pan to a wire rack to cool completely.

In a heatproof bowl microwave the remaining 1 cup butterscotch chips in 30 second bursts, stirring between bursts, until smooth. Drizzle over the bread. Let set before slicing and serving. Bread is best served the day it’s made but can be stored in an airtight container at room temperature for up to 2 days.