Lightly grease and line an 18 x 28cm slice pan with baking paper.
Combine biscuits and butter in a bowl until well blended.
Press into base of prepared pan.
Chill for 10 minutes.
FUDGE FILLING. Combine condensed milk, sugar and butter in a saucepan. Stir over medium heat until melted and combined.
Bring to the boil, stirring constantly for 4-5 minutes until thick. Remove from heat. Add chocolate, stirring until melted.
Pour over biscuit base. Sprinkle with pecans. Cover and chill overnight until firm. Using a hot knife, cut into small squares.
Store in an airtight container in the fridge.