Crush chocolate tea biscuits into fine crumbs and prepare instant coffee. Dip crumbs in coffee for 1-2 seconds and spread in a 9x13-inch pan.

Thaw kataifi dough, separate strands and sauté with butter until golden and crispy.

Combine sautéed kataifi with pistachio cream in a bowl and let cool for 10-15 minutes.

Chill bowl and whisk, then whip heavy cream and sifted powdered sugar until stiff peaks form.

Layer half of the pistachio filling over soaked biscuit base, add half whipped cream, repeat with remaining layers.

Heat heavy cream in a saucepan, pour over dark chocolate chips and stir until smooth. Cool slightly before drizzling over cake.

Cover the cake and refrigerate for at least 4 hours or overnight.