These sumptuous bars sport a chewy crust topped with coconut and chocolate-studded meringue. They're wonderful with a cup of coffee.
To make the crust: Preheat the oven to 375°F. Lightly grease a 9" x 13" pan.
Whisk together the all-purpose flour, nut flour, sugar, and salt.
Use a pastry blender or fork to thoroughly work the butter into the flour mixture.
Add the water a bit at a time, mixing until the mixture will hold together when squeezed, but is still crumbly.
Scatter the mixture into the pan. Press it into an even layer across the bottom and about 1" up the sides.
Bake the crust for 15 to 18 minutes, until set. Remove it from the oven and reduce the temperature to 325°F.
To make the topping: Beat the egg whites or meringue powder and water until foamy, then add the cream of tartar and salt. Omit the cream of tartar if you're using meringue powder. Beat until the mixture starts to form peaks.
Beat in the sugar a bit at a time, then add the vanilla and coconut flavor, and beat until the mixture is shiny.
Fold in the nut flour, coconut, and about 3/4 of the chocolate and nuts.
Spread over the crust and sprinkle with the reserved chocolate and nuts.
Bake the bars for 45 to 55 minutes, until they're lightly browned and crisp. Remove them from the oven; garnish with unsweetened coconut flakes. Cool completely (for about 2 hours) before cutting into bars. Store at room temperature, well-wrapped, for several days; freeze for longer storage.
