Preheat the oven to 160ºC (325ºF) and line an 8x8 inch square pan with parchment paper.

Crush the digestive or graham crackers and mix with melted unsalted butter to form the cookie crust. Press into the bottom of the pan and bake for about 10 minutes.

Melt semi-sweet dark chocolate chips and butter in a saucepan over low heat. Remove from heat and whisk in cocoa powder, granulated sugar, dark brown sugar, and eggs. Fold in flour, cornstarch, and salt.

Pour the brownie batter over the baked cookie crust and bake for 30 to 35 minutes until edges are set and center is slightly underbaked.

For the meringue, combine egg whites and granulated sugar over simmering water until sugar dissolves. Whip until stiff peaks form and fold in vanilla bean paste.

Spread meringue over cooled brownies and toast with a kitchen torch until golden brown.

Cool completely before slicing into squares for serving.