Preheat oven to 350 degrees and butter muffin/cupcake pan (or line with cupcake holders).
Beat together butter and sugar. Add egg vanilla and beat well. Beat in flour and buttermilk.
Spoon into cupcake holders, filling 2/3 full. Bake for 16-20 minutes and let cool.
Beat egg whites until soft peaks form. Add confectioners' sugar, vanilla and orange juice and continue to beat until thick.
Transfer 1/3 of the icing to another bowl and color with black food coloring. Place in pastry bag with small tip.
Cover cupcakes with white icing.
Starting at the center of the cupcake, pipe a spiral of the black icing from the center to the outter edge. Then, drag the tip of a knife from the center of the spiral to the edge of the cupcake. Clean the knife and move about 1/2 in. to the left or right and drag the knife in the opposite direction from the outter edge to the middle of the cupcake. Continue in this way until you have worked your way around the cupcake and formed the cobweb.