1.To make toffeed pecans, line oven tray with baking paper. Combine sugar and the water in small saucepan; stir over heat, without boiling, until sugar dissolves. Bring to the boil; boil, uncovered, without stirring, until caramel in colour. Remove from heat, allow bubbles to subside; stir in butter and nuts. Pour mixture onto tray; cool. Break toffee into pieces.
2.Melt 100g (3 ounces) of the butter in small saucepan over low heat. Process biscuits until fine; with motor operating, add the melted butter, process until combined. Press mixture over base and side of 22cm (9-inch) round loose-based fluted flan pan. Place pan on tray; refrigerate 15 minutes.
3.Place ice-cream in large bowl; beat a with wooden spoon until barely softened. Spread ice-cream into tart shell, smooth surface; freeze overnight.
4.Chop remaining butter, place in medium saucepan with sugar; stir over high heat until smooth. Add condensed milk and golden syrup to pan; bring to the boil. Boil, stirring constantly, about 10 minutes or until sauce is caramel in colour. Remove from heat; stand 10 minutes then gradually stir in milk.
5.Slice bananas thickly. Spread cream over ice-cream; top with banana and toffeed pecans. Serve immediately drizzled with warm caramel sauce.
Toffeed pecans can be stored in an airtight container at room temperature for about 4 weeks.Note