Preheat oven to 350°F and prepare muffin pan with muffin liners.
Pour all ingredients into a large bowl or bowl of a stand mixer. Mix until combined.
15 ¼ ounces yellow cake mix with pudding in the mix, 3 large eggs, ¾ cup vegetable oil, ½ cup water, ¾ cup sour cream
Use a ¼ cup measuring cup or a small scoop to fill the muffin liners until they are halfway full.
Bake in a preheated oven for 18-22 minutes or until a toothpick inserted in the center comes out clean.
Remove the cupcakes from the oven. Transfer them out of the muffin pan and onto a wire rack to cool completely before frosting.
Chocolate Buttercream
Place the butter, vanilla, milk, and espresso powder (if using) into the bowl of a stand mixer.
1 cup unsalted butter, 3 tablespoons milk, 1 teaspoon pure vanilla extract, 1 teaspoon espresso powder
Sift the powdered sugar and cocoa powder into the bowl. Mix on low speed for about a minute then adjust the speed to medium. Continue to mix for about 2 to 3 more minutes until the buttercream is fully combined and fluffy.
3 ½ cups powdered sugar, ½ cup unsweetened cocoa powder
Decorate the cupcakes with the buttercream and serve. Store any leftovers in the refrigerator for up to 5 days.
Notes
The calories listed are an approximation based on the ingredients and a serving size of 1 cupcake with chocolate frosting. The calorie count does NOT include the sprinkles seen in the photos. Actual calories will vary. The cupcakes can be stored in your fridge, in a sealed container, for up to 5 days.
Nutrition Facts
Cake Mix Cupcakes with Chocolate Buttercream
Serving Size
1 cupcake
Amount per Serving
Calories
317
% Daily Value*
Fat
19
g
29
%
Saturated Fat
8
g
40
%
Trans Fat
0.4
g
Polyunsaturated Fat
5
g
Monounsaturated Fat
5
g
Cholesterol
49
mg
16
%
Sodium
222
mg
9
%
Potassium
65
mg
2
%
Carbohydrates
37
g
12
%
Fiber
1
g
4
%
Sugar
28
g
31
%
Protein
2
g
4
%
Vitamin A
342
IU
7
%
Vitamin C
0.1
mg
0
%
Calcium
61
mg
6
%
Iron
1
mg
6
%
* Percent Daily Values are based on a 2000 calorie diet.