Preheat the oven 180 degrees. Line in parchment paper on baking sheet. Sift wheat flour ,Corn flour,Cocoa powder and keep it aside.
In a bowl beat butter ,sugar and vanilla essence till pale and fluffy.
Add the flour mixture to this butter sugar mixture and mix well. Add the coffee decoction and mix well.
Spoon the batter into a piping bag fitted with wilton 1m nozzle .press rose shape on the baking sheet with parchment paper .bake in preheated oven for 12 to 13 minutes .