You can use cupcakes that are already made and ready to decorate or make your own, I took a recipe I liked and altered it for this... it still needs a little work to find the right balance but is quite good.
This recipe will make 6 cupcakes, you will need:
50 mL of margarine or butter
100 mL white sugar
2 mL vanilla
150 mL flour
50 mL vanilla pudding mix
1 mL salt
5 mL baking powder
90 mL milk
Start by preheating your oven to 350 F.
Cream the margarine and sugar together. Add in the egg and vanilla.
Mix the dry ingredients in a separate bowl and add to the creamed mixture alternately with the milk.
Bake them for 25 minutes.
For the blood I made a simple syrup (2 parts water to one part sugar, cook until the sugar is clear)
Then I purred some strawberries and a few blueberries and added that into the syrup, it wasn't quite red enough for me so I added 2 drops of food coloring.
Once your cupcakes are cooled continue to the next step where you carefully cut out the center, I liked using a spoon to make a good hole. Then spoon in some of the syrup leaving a little room to place some of the removed cupcake back on top.
Now just add your icing, I tried to use an icing tip to make it look like bandages on top, but it didn't work quite as I wanted... just need a little more practice and make the icing stiffer next time
I made the chocolate knifes on waxed paper using a toothpick to help me shape them, the coloring I added to the white chocolate didn't mix very well so I will have to see what works best for blending or buy some that is already colored.
Once they're shaped to how you like them just put them in the freezer, when you're ready spoon a little of the syrup where you want your knife to go to add some effect, and stab your knife into it.
Now the murdered cupcakes are done, and great for a halloween party!