Place the sour cream, buttermilk, vanilla, eggs, and vegetable oil into a large mixing bowl. Whisk until smooth. Then sift in the cake mix and stir until smooth--but not overmixed. Do not skip sifting the cake mix because the batter will be lumpy.

Using a cookie scoop, place the cake batter into the cupcake liners. Fill them about 2/3 full.

Bake for 20-23 minutes or until the cupcakes are lightly browned and a toothpick inserted into the middle of a cupcake comes out clean or with a few small crumbs. Do not overbake. After 5 minutes of cooling time, move the cupcakes to a cooling rack. Cool completely before frosting.

Use a mixer to beat the butter, vanilla, butter flavoring, and salt until creamy. Add the cream and stir. Add the powdered sugar a cup at a time and beat between each addition. If the frosting is too stiff, add more cream. If too soft, add more sugar.

Divide the frosting into 3 bowls. In the first bowl, place about 2/3 cup of frosting and set the bowl aside. Divide the rest of the frosting between the other two bowls. (Place more in one bowl than the other. You will need more yellow frosting than orange because it will be the color you use the most.)

Add yellow gel coloring to the bowl with the most frosting and stir. Add additional color if needed until the desired shade is reached.

Add orange gel coloring to the other bowl with a large amount of white frosting. Stir to make an orange-colored frosting. Add more orange if needed to reach the desired color.

Prepare 3 piping bags for the frosting by placing a round tip in each bag and cutting off the bag tips.

Add the white frosting to the bag with the small round tip. Add the yellow frosting to a bag. Finally, add the orange frosting to the last piping bag.

Start with the yellow bag of frosting. Hold the bag perpendicular (straight up and down) to the center top of a cupcake. Squeeze out the frosting while barely raising the tip from the cupcake so that it makes a round disc of frosting on the cupcake.

Repeat for each cupcake until all the yellow layers have been made. Next, add the orange frosting in the same manner as the yellow frosting. Make the orange layer a little smaller. Continue until all cupcakes have an orange layer. (If you run out of orange frosting, add a small amount of red gel coloring to the yellow frosting to make an orange color.)

Finally, add a white top to the top of the cupcakes. Make this layer small to resemble the tip of a piece of candy corn.

Garnish each cupcake with a piece of candy corn. Do not add the corn until just before serving the cupcakes because the frosting can break down the colors in the candy corn and cause the candy to drip on the cupcakes.