1.Combine cherries and sherry in small bowl, cover, stand at room temperature 3 hours or overnight.
2.Preheat oven to 160°C (140°C fan forced). Grease two deep 15cm (6-inch) square cake pans, line bases and sides with baking paper, extending paper 5cm (2 inches) over sides.
3.Melt butter and chocolate in medium heatproof bowl over medium saucepan of simmering water. Remove from heat, stir in sugar. Using electric mixer, beat in eggs, one at a time. Add sifted dry ingredients, beat on low speed until combined. Beat in sour cream, then stir in cherry mixture. Pour mixture evenly into pans.
4.Bake cakes about 1 hour 20 minutes, cool cakes in pans.
5.Make chocolate ganache. Combine ingredients, chocolate, cream and glucose in small heatproof bowl over small pan of simmering water. Stir until smooth. Stand about 20 minutes or until spreadable.
6.Place cakes on serving plates, spread ganache over cakes.
Glucose helps give the ganache a glossy look. Glucose syrup is available from most supermarkets in the baking aisle. Cakes may be stored in an airtight container in the refrigerator for up to one month, or frozen for up to 3 months, however, the ganache will not be as glossy after freezing.