Pre-heat the oven to 160°C/325°F. Grease a 13 inch x 9 inch pan generously with cooking spray and set aside.
Add brown sugar, cinnamon and nutmeg to a small bowl. Thoroughly mix. Set aside.
In a mixing bowl cream together the butter sugar and oil until it’s fluffy and starting to look white – about 3 minutes. Add sour cream and mix for another minute.
Stir in the eggs, a little at a time, beating the mixture well between each addition.
Sift in the flour, salt and baking powder into the batter, and vanilla extract.
Stir well until everything is fully combined. Scrape down the sides of the mixing bowl.
Pour half of the batter into the greased pan. Then Sprinkle about ¾ of the sugar mix over the batter in the pan. Spread the remaining batter evenly over sugar cinnamon mix.
Next sprinkle the remaining cinnamon sugar mix on top of the cake. Make swirls with spoon , if desired.
Bake at 325°F. until a tester inserted into the center comes out clean – about 40 minutes.