1-2tablespoonsof milk, just enough to make it the proper consistency
For the chocolate ganache:
2½ouncessemi-sweet or bittersweet chocolate, chopped
For the cupcakes:
Preheat oven to 350 degrees (F). Grease (or line with paper liners) a cupcake tin; set aside.
In a medium bowl mix together the flour, baking soda, baking powder, cocoa powder, and salt. Set aside.
Combine water and sugar in a small saucepan and bring to a simmer over medium-high heat. Allow the mixture to simmer – stirring occasionally – until the sugar has completely dissolved.
Remove pan from heat and stir in the butter and chocolate; whisk until both are completely melted. Whisk in oil. Add vanilla, then let mixture cool 10 minutes before quickly whisking in milk and eggs.
Fold the flour mixture into the liquid mixture, and mix until combined.
Pour batter into prepared pan and bake for 15 - 18 minutes, or until a cake tester comes out clean.
Allow the cupcakes to cool in the pan for at least 10 minutes before transferring to a cooling wrack to cool completely.
For the filling:
In the body of a stand mixer fitted with the paddle attachment beat the butter and cream cheese on medium speed until light and fluffy; about 3 minutes. Gradually add the sugar, then mix in the vanilla and milk.
Divide the filling into two separate ziplock bags, then snip the edges off, one large and one VERY small. The larger end will be what you use to fill the cupcakes, and the small one is for the writing on the cupcakes.
For the Ganache:
Place the chopped chocolate in a small bowl; set aside.
Pour the cream in a small saucepan and bring to a gentle simmer over medium heat. Remove from the stove, and immediately pour over the warm cream over the chopped chocolate.
Let stand for 2 minutes, then gently whisk together until it forms a smooth ganache. Set aside to thicken for 5 to 10 minutes.
Using a 1-inch round cutter (or a small parring knife), carefully cut the centers out of the cupcakes, going about two-thirds of the way down. Using the large tipped prepared filling bag, pipe filling into the holes of each cupcake. Scrape tops smooth.
Once all of the cupcakes are filled, take them one at a time and dip them into the chocolate ganache. Dip them down to where the cupcake liner starts, so that the entire top is covered. Allow any excess ganache to drip off and back into the bowl, then place back on the cooling rack.
Once all of the cupcakes have been topped with ganache, transfer the cooling rack to the refrigerator for 30 minutes to allow the ganache to set.
Once the ganache is firm, take your pastry bag with the tiny tip and pipe any words, decorative curls, or funny little pictures across the top of each cupcake. Serve at once! Or store in an airtight container for up to two days.