Pre-heat oven to 160°C. Line a large, flat biscuit tray with baking paper.
In a medium sized bowl, using electric beaters, cream together butter and sugar.
Using a spatula, gently fold FATE mix into butter and sugar, 2 3min., until mixture resembles fine breadcrumbs. Make a well in the centre.
In a small bowl, combine water, egg replacer, and essence; pour into FATE mix centre. Using the spatula, fold all ingredients together until a firm dough is formed.
Sprinkle extra FATE mix on clean workbench. Using a rolling pin, flatten dough until ½- ¾ cm thick. Cut out shapes, using your choice of cookie cutter/s.
Place cookies on prepared tray, bake 20min., until just light browned on top. Transfer to a wire rack to cool. Meanwhile, prepare icing.
Using electric beaters, mix together icing sugar, water, and essence until well combined (you may need to add a a little extra water). However, the mixture should firm, not runny.
Add glucose syrup and mix, using electric beaters, further 1min., until icing is smooth.
Using a knife, spread icing over cooled biscuits. Decorate with sprinkles if using.