Preheat oven to 350 degrees F.
In a large bowl combine the cake mix, instant pudding, sour cream, and vegetable oil. Mix together using the whisk attachment on low speed until the ingredients just come together.
Add the eggs 1 at a time, mixing after each egg until it is incorporated into the batter.
Prepare a muffin pan by lining each tin with a cupcake wrapper.
Scoop approximately 3 tablespoons of batter into each muffin cup.
Place the cupcakes in the oven and bake for 18-22 minutes, or until a toothpick stuck in the center comes out clean.
Remove from the oven and let cool completely.
While the cupcakes cool make the buttercream frosting. Add butter and powdered sugar to the bowl of your mixer and using the whisk attachment mix it together. Start slow so the powdered sugar doesn’t go everywhere them move to a higher speed to whip the frosting and make it light and fluffy.
Add the vanilla extract and lemon extract and continue to mix. If you want to color your frosting add 1-2 drops of yellow food coloring now.
If the frosting is still too firm add the milk 1 teaspoon at a time, mixing well in between each, stopping when you reach the right consistency.
When the cupcakes are completely cooled place the frosting in a piping bag and pipe the frosting onto each cupcake.
Serve and enjoy!