- To make your cookie base, combine flour, cornstarch, baking soda, both your sugars, chocolate chips in a large bowl and whisk together. Then add melted butter, egg, egg yolk and vanilla. Mix thoroughly until completely combined, then add mixture to a pie or tart dish.
- Press the mixture into the pie dish to create a cookie dough base and sides. Cover with parchment paper, then baking beans and bake for 35 mins at 180 degrees.
- While your cookie dough base bakes, make the chocolate ganache. Heat double cream and sugar until boiling. Add your chocolate to a bowl and pour the hot cream over the chocolate, mixing well until the chocolate has completely melted. Add your nuts and set to one side.
- In a small pan, combine sugar and water. Heat over high heat, stirring only until it comes to a boil. Once it reaches a boil, stop stirring. Cook until sugar syrup registers 115°C.
- Meanwhile, combine egg whites and cream of tartar in the bowl of a stand mixer fitted with a whisk attachment . Set the mixer to medium speed and mix until soft peaks form about 2 minutes.
- With the mixer running, carefully and slowly drizzle in hot sugar syrup. Increase speed to high and whip until desired stiffness is achieved. Add in your coffee mixture and give one final whisk.
- Now your cookie base has baked, add the ganache to the base and chill until the chocolate has set, about 2 hours.
- Remove the tart from the fridge and dollop your meringue on top of the ganache, spreading evenly but also forming peaks.
- Using a blow torch, toast the marshmallow and serve!