1/2 cup butter
2/3 cup sugar
2 tbsp canola oil
2 large eggs
1 tbsp vanilla extract
3/4 tsp baking powder
3/4 tsp baking soda
1 1/4 cups cake flour
1/4 cup cornstarch
2/3 cups buttermilk
Preheat oven to 350°F. Line a standard 12 muffin tin with baking papers.
Beat the butter and sugar until light and fluffy. Beat in the the oil, then beat in the eggs one at a time.
Beat in the vanilla, baking powder and baking soda. Stir in all of the flour, cornstarch and buttermilk, then beat until well combined; less than a minute.
Spoon the batter, dividing equally among the 12. Bake for about 13-15 minutes or until done. Remove from oven immediately and cool completely before frosting. Be careful not to leave them in the oven too long otherwise they might dry out and won't be moist.
chocolate sour cream frosting
6 oz good quality semisweet chocolate chips
1 1/4 cups sour cream, give or take a tablespoon or two.
sprinkles for decorating
Carefully melt the chocolate chips. Whisk in the sour cream until well combined. Frost the cupcakes immediately. Top with sprinkles.
These are best eaten the day they are made.