My homemade Batman birthday cake consisted of 12 cupcakes and a 6″ cake using a vanilla cake mix.
I made buttercream icing from a C&H Sugar recipe and colored it black and yellow. I piped the cupcakes with black icing using #12 tip. I leveled the 6″ cake and crumb frosted it. I then turned it upside down on the board, attaching it to the board using icing; this acts as glue and keeps the cake on the board when you ice it. Turning the cake over allows for less crumbs when frosting. I let it sit then finished icing it.
I piped a black bead border and sprinkled black sugar on the top of the cake. Three or four days prior, I made the cupcake toppers and the black bat on the cake out of MMF. I cut yellow fondant with an oval cutter and used my cricut to cut out a paper bat. I then cut out the black bat for the emblem with an exacto knife and pieced it together. I use a touch of water as glue.
It was a big hit for the birthday boy when they came to pick it up!