For the waffles:
Preheat waffle iron (if iron has multiple heat settings, choose medium heat).
Melt butter in small saucepan on medium heat. Add chocolate chips and stir until chocolate is melted completely into butter. Remove from heat and cool until warm, not hot.
In small bowl, whisk together sugar, eggs, vanilla extract and buttermilk. Stir into chocolate mixture until completely combined.
In another small bowl, whisk together flour, salt and baking soda. Stir into wet ingredients a little at a time until just combined.
Grease waffle iron and fill each section with small layer of batter. Cook for about 4 minutes or until fully cooked (times will vary based on your waffle iron model). Remove each section and set on a cooling rack to cool. Repeat until all batter is used.
For the German chocolate topping:
While waffles are cooking, combine sugar, evaporated milk, butter and egg yolks in medium saucepan on medium-low heat. Periodically stir until mixture thickens to porridge-like consistency, about 15 minutes. Remove from heat.
Stir in vanilla extract, coconut flakes and pecans. Top each cooled waffle cookie with German chocolate topping. Serve within 24 hours.