250g butterCream butter until very soft. Add vanilla and icing sugar and continue beating until nearly white in colour (you will need an electric beater or a strong friend!). Sift in the flour in three portions, stirring quickly after each addition. Press into a greased, shallow 30 x 20 cm tin, prick all over with a fork and bake around 40 minutes at 160 degrees until it is pale gold and starting to get firm. Leave to cool in the tin for 30 minutes or so then cut into squares while still a bit warm (if it's crumbly it needs to cool some more). Store in an airtight container.
1 tsp vanilla essence
2/3 cup icing sugar
2 cups + 3 T white flour
Makes about 30 squares