Fill a cocktail glass with ice cubes and set it aside.
To make the red layer, place the spiced rum, grenadine, cranberry juice, and gold dust into a cocktail shaker with ice.
Shake well for 15-30 seconds to combine.
Strain into the ice-filled glass.
To make the black layer, place the black vodka, Creme de Cassis, lemon-lime soda, and gold dust into a cocktail shaker with ice.
Shake well for 15-30 seconds to combine.
Pour the black cocktail mixture on top of the red layer.
Garnish cocktail with fresh mint and/or cherries. Enjoy, and Happy Halloween!