Preheat the oven to 350°F and line a muffin tin with 24 cupcake liners.

Combine the cake mix, buttermilk, eggs, and oil in a large bowl and mix until smooth.

Divide the batter evenly into the liners, filling each about two-thirds full.

Bake for 18–22 minutes, or until a toothpick comes out clean.

Cool cupcakes completely before decorating.

In a large bowl, beat cream cheese and butter until smooth.

Add powdered sugar gradually and mix until combined.

Add vanilla extract and whip until thick and creamy.

Refrigerate frosting if preparing ahead, then bring to room temperature before using.

Combine granulated sugar, water, corn syrup, and cream of tartar in a saucepan.

Heat over medium-high without stirring until the mixture reaches 300°F (hard crack stage).

Quickly pour onto a parchment-lined baking sheet and spread thin.

Cool completely, then break into shards using the back of a spoon.

Combine raspberries, sugar, and lemon juice in a saucepan over medium heat.

Cook for about 10 minutes until raspberries break down and sauce thickens slightly.

Strain through a fine mesh sieve to remove seeds.

Cool completely before using.

Frost cooled cupcakes with cream cheese frosting.

Insert sugar glass shards into the frosting.

Spoon raspberry sauce over the shards and frosting, allowing it to drip for a bloody effect.

Serve immediately or refrigerate until ready.