Combine frozen raspberries, granulated sugar, and water in a small saucepan.
Cook over medium heat for 5–8 minutes, stirring occasionally, until the raspberries break down into a coulis.
Pour ⅔ of the coulis into small silicone moulds or an ice cube tray and freeze at least 1 hour to make the frozen inserts.
Refrigerate the remaining coulis to use as a drizzle later.
Preheat oven to 220°C (425°F).
In a large bowl, beat the eggs with granulated sugar until light and foamy.
Stir the softened butter into the egg mixture.
In a separate bowl, combine the all-purpose flour and baking powder.
Alternate adding the flour mixture and the milk into the egg mixture, stirring until the batter is smooth.
Line a muffin tin and fill each liner halfway with batter.
Place one frozen raspberry insert cube into the center of each muffin liner.
Cover each insert with a little more batter, filling the liners about ¾ full.
Bake for 15 minutes or until golden, then cool completely.
In a bowl, whip the cold heavy cream until it begins to thicken.
Add the powdered sugar, vanilla extract, and red food colouring to the cream.
Continue whipping until stiff peaks form.
Transfer the whipped cream to a piping bag fitted with a fluted tip and refrigerate until ready to pipe.
In a small saucepan, melt the granulated sugar over medium heat without stirring until it reaches an amber colour.
Remove the pan from the heat and quickly stir in the red food colouring.
Pour the hot caramel onto parchment paper or a silicone mat and spread it thinly.
Let the caramel cool completely, then break it into shards to resemble broken glass.
Pipe the chilled whipped cream on top of each cooled muffin.
Drizzle the reserved raspberry coulis over the cream for a bloody effect.
Decorate each muffin with shards of red caramel broken glass.