Preheat oven to 350 degrees. Put cupcake papers in 2 muffin pans (24 total).
Combine the chocolate chips and hot coffee, stirring until the chocolate has melted and the mixture is smooth. Let stand.
In a medium bowl, sift together the flour, sugar, cocoa powder, baking powder, and baking soda. In a larger bowl (everything will be eventually going into this one) beat the two eggs until thickened and lemon colored, about 5 minutes with a hand mixer. Add the oil, buttermilk, vanilla, and chocolate mixture, beating after each addition. Add the dry ingredients, beating until combined.
Divide batter between the cupcake cups and bake for 12-15 minutes, until a toothpick inserted into a cupcake comes out clean.
Remove to racks to cool.