oven to gas 4. Lighlly grease 20cm/8in springform in. In small non-stick pan gently heat butter, sugars, chocolate, syrup, stirring until chocolate melted, mixture smooth. Remove from heat, leave to cool. In a bowl, beat egg and vanilla, add to cooled mixture. Sift in flour and baking powder, mix well. Pour into the tin, bake 15 minutes until outside of the brownie is crisp and beginning to shrink away from sides but centre soft to the touch. Leave to cool. Make ice cream melt chocolate. Whip cream until it just holds its shape, then whisk in the cold custard. Stir in chocolate until mixture is thick, smooth, well blended. Pour onto cooled brownie, tilt tin to level top. Melt plain chocolate, with a tsp drop dozen neat blobs onto the ice cream 3 cm from edge. Open freeze 4 hours. Remove, dust with powder.