Add greek yogurt and condensed milk to a medium bowl and beat with an electric mixer until whipped. Set aside.

Combine the milk, espresso and sugar in a small bowl.

Using a brush, lightly coat the savoiardi with the espresso mix being careful not to get them too wet.

Spread on yogurt mixture and dust the top with cocoa.

Freeze for 30-40 minutes or refrigerate for a couple hours (or overnight). Serve with a generous dusting of cocoa powder.