Preheat oven to 350 degrees.

In a large bowl, sift the sugar and flour together.

In a saucepan on the stove, mix the butter, vegetable oil, cocoa and Coca-Cola® together. Bring to a boil and pour over dry ingredients blending together well.

Dissolve the baking soda in the buttermilk and immediately add to the batter along with the two eggs, and the extract. Mix together well.

For a Cake: Pour into a well-greased 9- by-13-inch pan and bake 35 to 45 minutes.

For Cupcakes: Pour into mason jars about 1/3 full. (they will rise a lot). Place the mason jars in a pan and bake for 25-35 minutes. I checked them a lot. I removed them when a toothpick came out clean (at about 30 minutes).

Remove from oven and frost immediately.

Combine the butter, cocoa and Coca-Cola® in a saucepan over medium heat. Bring to a boil.

Sift the powdered sugar into the boiling cola/butter mixture, blending together well.

Add the vanilla extract and the pecans.

Spread the frosting over each cupcake. Allow to cool.

Serve.

For Cake: Refrigerate in covered container for up to a week.

For Cupcakes: Screw the lid on the mason jar and store in refrigerator for up to a week.