Grease a non-stick 20cm loose based fluted pie tin. Sift flour into a mixing bowl and add diced butter. Blend with a pastry cutter until mixture resembles fine breadcrumbs.
Stir in sugar and essence and mix well. Add the combined egg and water, then knead lightly until a soft dough is formed. Wrap the dough in cling film and chill in the refrigerator for 30 minutes.
Remove dough and roll between two pieces of plastic sheets into a thin circle that is big enough to line the pie tin.
Ease the pastry dough into the bottom of the pie tin and press out the excess. Trim off excess dough from the edge of the tin.
For the filling, beat butter, sugar and salt until fluffy. Add eggs, one at a time beating well after each addition. Mix in corn syrup, brandy (optional) and vanilla essence.
Blend in melted chocolate, pecans and sift in flour to mix. Pour chocolate filling into the prepared mould until 80% full. Bake in a preheated oven at 160°C for about 25-30 minutes or until filling is set and done.