Mix melted butter and sugars together in a bowl.
Stir in egg yolks and vanilla.
In a separate bowl, whisk together flour, baking powder, corn starch, baking soda, and salt.
Stir flour mixture into butter mixture just until combined.
Refrigerate dough for 30 minutes.
Preheat oven to 350 degrees.
Line a 9x13 baking dish with parchment paper.
Press cookie dough into bottom of dish.
Sprinkle on chocolate chips, coconut, and pecans.
Beat egg whites until foamy.
Beat in one cup of brown sugar, adding one tablespoon at a time.
Continue beating until stiff and glossy.
Spread meringue over the top of the chocolate, chips, coconut, and pecans.
Bake for 30-35 minutes or until set. (Do not overbake.)
Cool completely before cutting.
Store in airtight container.