For the dough:
1) In a medium mixing bowl, sift together the flour, salt and cinnamon. In a large mixing bowl, using an electric mixer, cream the butter, granulated sugar and dark brown sugar.
2) Beat in the egg whites and vanilla and butter flavour essences. Carefully fold in the flour mixture using a rubber spatula.
3) Wrap the dough in cling film and chill until firm, about 30 mins in the freezer.
For the peach cobblers:
1) Preheat the oven to 180C/Gas 4. In a medium mixing bowl, mix the peach preserves with cinnamon, nutmeg, lemon zest and lemon essence.
2) When the dough has chilled, roll it out to 1/2cm thick and cut into pieces about 6cm wide and 7 1/2cm long.
3) Place 1 tsp of peach filling in the centre of each piece and fold each end of the dough to the centre to cover the filling.
4) Flatten the cobblers slightly and place them seam down and 2cm apart on a parchment-lined baking tray.
5) Bake for about 12 mins, until lightly browned and just firm. Allow to cool.
6) Dust the cobblers with a mixture of icing sugar and cinnamon, if using.