Step 1

Preheat oven to 160C/140C fan forced. Release base of a 22cm (base measurement) springform pan. Invert. Line with baking paper. Secure in pan, allowing edge to overhang. Grease side with melted butter.

Step 2

Melt chocolate, butter, sugar and water in a heatproof bowl over a saucepan of simmering water. Remove from heat. Stir in flours, cocoa and egg. Pour in pan. Bake for 25 minutes or until a skewer comes out clean.

Step 3

Cool cake completely in pan. For mousse, place chocolates in a heatproof bowl over a saucepan of simmering water (don't let the water touch the bowl). Stir for 3-4 minutes or until melted and smooth.

Step 4

Remove from heat and set aside to cool slightly. Use electric beaters to beat cream in a bowl until soft peaks form. Fold a third of the cream into the chocolate mixture. Repeat twice until well combined.

Step 5

Spoon mousse into the pan. Tap on the bench a few times to remove any air pockets. Use a spatula to smooth the surface. Place in the fridge for 6 hours or overnight to chill and set.

Step 6

For the glaze, combine chocolate, cream and glucose in a small saucepan. Stir over low heat until melted and smooth. Cool slightly. Pour over mousse. Place in the fridge for 1 hour to set. Serve cut into wedges.