Preheat oven to 350°F (175°C). Line a 12-cup muffin tin with paper liners.
In a medium bowl, whisk together flour, cocoa powder and salt.
In a large bowl, beat butter, oil and sugar with an electric mixer until light and fluffy, about 3 minutes (you can use a stand mixer if you have one). Add eggs one at a time, beating well after each addition. Mix in vanilla extract and red food coloring. the buttermilk, oil, red food coloring, vanilla and vinegar.
(Do this part by hand with a rubber spatula to avoid over-mixing.) Add the flour mixture in three parts, alternating with the buttermilk, beginning and ending with the flour mixture. Mix until just combined.
In a small bow, mix together the vinegar and baking soda (it will fizz); stir immediately into the batter.
Divide batter evenly among cupcake liners, filling each about ⅔ full (I use a scant 1/4 cup each for 14 cupcakes). Bake for 15 - 17 minutes, or until a toothpick inserted in the center comes out with just a few crumbs. Cool in the pan for no more than 5 minutes, then transfer to a wire rack to cool completely.
Prepare the Berry "Blood" Syrup: Combine the raspberries, sugar, and lemon juice in a saucepan over medium heat. Bring to a simmer and cook for about 10 minutes, smashing the berries with a spoon as they break down. Cool for several minutes, then strain through a fine-mesh sieve to remove seeds and pulp. Allow to cool completely (it will thicken as it cools), then transfer to a squeeze bottle. The syrup should be thick enough to drip slowly but not run completely off the cupcakes. (If your syrup is really thin, stir in the corn starch slurry and heat over medium heat for another 1 to 2 minutes; then cool.)
(*If using strawberries, follow this method: after cooking, purée the mixture using an immersion blender or regular blender, then strain through a fine-mesh sieve. If you'd like a deeper red, add a few drops of food coloring until it's the color you like.)
Make the Pink Frosting: In a large bowl, beat cream cheese and butter until smooth and creamy. Gradually add powdered sugar, beating well after each addition. Beat in vanilla extract, a pinch of salt, and pink food coloring until you achieve a pretty pink shade reminiscent of Carrie's prom dress. (If the frosting is too soft for piping, add more powdered sugar; if it's too stiff, add milk a teaspoon or two at a time.)
Decorate the Cupcakes: Fill a piping bag fitted with a round or star tip with the pink frosting. Pipe the frosting onto each cupcake in a circular motion beginning at the outside edge. Place a crown pick or topper on each cupcake.
Just before serving, use the squeeze bottle (or spoon) to carefully drip the "blood" syrup over each cupcake.