Dissolve 1 tablespoon of instant coffee in 2 tablespoons of hot water, stir until fully dissolved, and allow to cool.

Cream together 1 stick of softened unsalted butter with 1 cup of icing sugar until light and fluffy.

Incorporate 1 large beaten egg into the butter and sugar mixture until fully combined.

Whisk together 2 cups of all-purpose flour, 1 tablespoon of cornstarch, and 1 teaspoon of ground cinnamon in a separate bowl.

Fold the cooled coffee mixture into the creamed butter mixture and gradually add the dry ingredients until just combined.

Transfer the cookie dough into a piping bag and pipe small rosettes onto a lined baking tray.

Chill the piped cookies in the freezer for about 5-10 minutes.

Preheat the oven to 350°F (175°C) and bake the cookies for approximately 8 minutes until lightly golden.

Once cooled, dip the cookie edges into melted dark chocolate and sprinkle with chopped pistachios.