Preheat oven to 350 degrees. Grease and flour a 9x5 inch loaf pan.

In a large bowl combine the flour, baking powder, salt, cinnamon and sugar.

In a small bowl whisk together the egg, milk or Half and Half, vanilla and sour cream.

Add the wet ingredients to the dry ingredients and stir to combine. Pour about half of the batter into your prepared pan.

In a small bowl combine the ingredients for the cinnamon swirl. Dollop spoonfuls of the mixture over the batter in the pan. Use a knife to gently swirl the cinnamon mixture into the bread.

Add the remaining batter to the pan, followed by the remaining cinnamon swirl mixture, and run the knife through the batter again.

Bake for 45-50 minutes or until you insert a toothpick and it comes out clean. Remove the bread from the oven and transfer it to a cooling rack to cool for 10-15 minutes before turning it onto a wire rack to cool completely.

Meanwhile, combine the ingredients for the glaze in a small bowl. Drizzle the glaze over the cooled bread.