In a medium bowl combine the all-purpose flour with baking powder and salt. Stir to blend.

In a small bowl combine water, Marsala wine and cornstarch. Mix well to obtain a liquid mixture. You will need to stir it again right before adding to the cookie dough because the starch tends to coagulate.

In a large mixing bowl combine sugar and melted butter and whisk. Add the starch mixture and whisk again. Add the mascarpone and whisk well to remove any lumps.

Gradually add the flour mixture, folding it gently with a wooden spoon. Make a dough. At the end fold the instant coffee around the dough.

Place the dough in the fridge for 30 minutes.

Line two large baking tins with parchment paper.

Make small balls out of the dough and place them on the baking sheet Sprinkle with cocoa powder.

Bake the cookies for 10-12 minutes at 350° F/ 180° C with the tin placed at the upper part of the oven. The cookies are ready when they are golden brown on the edges but the tops are still soft.

Let the cookies cool to room temperature before frosting them.

Place the mascarpone cheese, powdered sugar, instant coffee and Marsala wine in a medium bowl. Whisk very well until smooth and creamy.

Frost the cookies shortly before serving them using a small teaspoon or a frosting spatula.

Sprinkle cocoa powder on top.