Best Chocolate Cupcakes

Ingredients:

Chocolate Cake:
1 1/2 sticks (12 tbsps) Unsalted Butter
2/3 cup White Granulated Sugar
2/3 cup Dark Brown Sugar, packed
2 large Eggs
2 tsps Pure Vanilla Extract
1 cup Buttermilk
1/2 cup Sour Cream

2 tbsps Brewed Coffee
1 3/4 cups All Purpose Flour
1 cup Unsweetened Cocoa (Recommended: Ghirardelli)
1 1/2 tsps Baking Soda
1/2 tsp Fine Sea Salt
Italian Meringue Buttercream:
1 1/4 cup White Granulated Sugar
1/4 cup Water
5 large Egg Whites
3 1/2 sticks (28 tbsps) Unsalted Butter, cut into tbsps
Peanut Butter (Optional)
Bittersweet Chocolate (Optional; Recommended: Ghirardelli)

1. Preheat oven to 350 degrees.
2. In the bowl of a stand mixer fitted with the paddle attachment, cream the butter and sugars together for 5 minutes on high speed. Mixture will become pale and fluffy. After lowering the speed to medium, add the eggs one at a time. Add the vanilla next, and blend well.
3. In a measuring cup, combine the 1 cup of buttermilk, the sour cream, and the brewed coffee. Mix everything together. In a separate bowl, combine the flour, unsweetened cocoa, baking soda, and fine sea salt. Mix these ingredients together, as well. Turn the mixer's speed to low, then add the wet ingredients and dry ingredients alternately in thirds. Start with the wet ingredients, and end with the dry ingredients. Mix until batter is smooth.
4. Divide the cake batter into muffin pans prepared with paper liners, about 2 tablespoons each for 24 cupcakes. Bake at 350 degrees for 14-16 minutes, until a toothpick inserted into the middle of a cupcake comes out clean. Remove from the oven, and allow to cool in the pan for 2 minutes. Then, transfer cupcakes to a cooling rack and cool completely before frosting.
5. To make the frosting, combine 1 cup of the sugar and the water in a small saucepan over medium-high heat. Gently stir with a wooden spoon just until the sugar is dissolved, then do not stir. Attach a candy thermometer to the pan to monitor the temperature of this sugar mixture. While this is heating, place the egg whites in the *CLEAN* bowl of a stand mixer fitted with the *CLEAN* whisk attachment. Whip for 2-3 minutes on high speed until soft peaks form, then sprinkle in 1/4 cup of sugar. Continue to whip until stiff peaks form. 
6. Once the sugar mixture has reached 245 degrees, or the "soft-ball stage", slowly pour the syrup into the meringue, with the mixing speed reduced to medium. When pouring, aim for the space between the bowl wall and the revolving whisk. Continue to whip the meringue for another 7-8 minutes until cooled to room temperature. Add the butter one tablespoon at a time, then increase the mixing speed to high and mix until the buttercream has fully combined and become smooth.
7. *OPTIONAL* To make peanut butter buttercream, add creamy peanut butter (3-4 tbsps = 1/2 batch; 6-8 tbsps = full batch) to the buttercream. To make chocolate buttercream, melt bittersweet chocolate chips (4 tbsps = 1/2 batch; 8 tbsps = full batch) and allow it to cool to room temperature. Fold the chocolate into the buttercream.
8. Top the cooled cupcakes with italian meringue buttercream, and decorate as desired. Enjoy!

by : here