2 cups powdered sugar, plus more for sprinkling on cake.
Instructions
Stir raspberries and powdered sugar in a saucepan over medium heat. Stir often. When the raspberries release juice, raise the heat, stir occasionally and simmer until the mixture thickens slightly (about a minute).
Let cool. Process in a blender or use an immersion blender to make a smooth sauce.
Add a dusting of powdered sugar on top of the cake.
Pour raspberry drizzle over cake in a zig-zag motion.
If you have extra sauce, it will keep in the fridge for about a week.