For the cupcakes:
1/2 cup unsweetened cocoa
1/2 cup boiling water
1-1/2 cups sifted cake flour (sift, then measure)
1 cup granulated Splenda
1/2 tsp baking soda
1/4 tsp salt
3/4 cup (1-1/2 sticks) butter, at room temperature
2 large eggs, lightly beaten
1/4 cup whole milk
1 tsp pure vanilla extract
For the frosting:
2 oz unsweetened chocolate (I used Trader Joe's)
1/3 cup heavy whipping cream
1/2 cup butter, softened
4 Tbsp Splenda (6 small packets)
1 tsp pure vanilla extract
1 tsp chocolate extract or strong prepared coffee
Preheat oven to 350°F. Line cupcake tin with paper liners.
In a small measuring cup, combine cocoa and boiling water. Whisk and blend until smooth, and set aside.
In the bowl of a stand mixer fitted with the paddle beater, combine flour, Splenda, baking soda and salt. Add butter and mix until the mixture is crumbly.
In a separate bowl, combine eggs, milk, cocoa mixture and vanilla. Add 1/3 of this wet mixture to the mixer bowl. Beat on low speed until every thing is combined, then increase to medium speed and beat for an additional 30 seconds. Scrape down the bowl, and add another 1/3 of the wet mixture to the mixer bowl. Repeat, until all of the wet mixture has been added and the batter is smooth.
Using an ice cream scoop with a release (called a "disher"), or a large spoon, scoop the batter into the cupcake tin.
Bake 18 minutes or until a toothpick inserted in the center comes out clean. The cupcakes will not be smooth on top, but that's okay. Remove the cupcakes from the pan onto a wire rack, and let them cool completely.
While the cupcakes are cooling, make the frosting:
In a glass measuring cup, heat the chocolate in the microwave in 30-second increments until it's almost completely melted (this took three 30-second zaps), then stir until it is smooth, and pour it into the bowl of a stand mixer to cool for a couple of minutes.
Using the whisk beater on your mixer, slowly whisk the cream into the cooled chocolate. Beat on medium speed and add the butter, Splenda, cocoa, vanilla and chocolate extract or coffee. Beat until smooth and fluffy, approximately 3 minutes.
If you want to spread the frosting with a palette knife, you can do it now. If you want to pipe it through a pastry bag (or in a zip-loc bag with one corner snipped off), fill your pastry bag. If it doesn't pipe easily, put the pastry bag into the refrigerator for 20-30 minutes so the icing can stiffen up a bit. (I found it easy to pipe right away, without chilling it.)
These cupcakes don't keep well, so serve them the same day you make them.