Preheat oven to 180C and prepare 2 loaf pans.
In a small bowl mix most of the cinnamon and 6 tablespoons of sugar together and set aside.
In another bowl mix together flour, baking powder, salt and 1 teaspoon cinnamon and set aside.
In your electric mixer (or a large bowl), cream the butter, sugar and oil on medium speed for about 1 minute.
Add the eggs and mix.
Add the vanilla and yogurt and mix until just combined.
Add in the flour mixture and stir by hand until just combined.
Scoop a 6th of the batter into each loaf tin, sprinkle a thick layer of cinnamon sugar over the batter, repeat 2 more times, ending with a cinnamon sugar layer.
Bake for about 40-45 minutes.
Remove from oven and allow to cool before removing from the tins.
Serve warm with a little butter spread on.
Adapted from Betty Crocker