Stir together cinnamon and sugar and pour onto a small bread plate.
Slice a grape in half and run it along the rim of two highball glasses then twirl the rim of each glass in cinnamon sugar. Fill each glass with ice and set aside.
Add vodka and grape juice to a large cocktail shaker and shake vigorously until well blended.
Strain the juice mixture into each glass until halfway full then top off the cocktails with the Elderflower hard cider and stir.
Garnish with a skewer of grapes and apple slices and serve immediately.