Make the ganache first: melt chocolate, cream, butter, and glucose syrup together, then cover and let set at room temperature for 3 to 4 hours.
Preheat oven to 300°F (150°C) fan forced. Grease and line two 8 inch round cake pans.
Melt the chocolate and butter together until smooth.
Stir in the oil, vanilla, and sugar, then whisk in the eggs.
Sift in the flour, cocoa powder, baking powder, baking soda, and salt. Stir until combined.
Stir the coffee into the boiling water, then whisk into the batter. It will be thin.
Divide between the pans and bake 40 to 45 minutes, until a toothpick comes out clean.
Cool completely, then soften the ganache and layer and frost the cake.