Source: Fine Cooking UPDATES: 1/23/2024: In an effort to achieve that shiny, crackly crust every time, I've made a few changes to the recipe, mostly to the method, which is reflected in the instructions below. I also now use 3 eggs as opposed to 4, 1 tablespoon vanilla as opposed to 1/2 teaspoon, and 1 teaspoon Diamond Crystal kosher salt as opposed to 1/2 teaspoon table salt. Notes: A digital scale is best for measuring flour and cocoa powder. This one is reasonably priced. Buy it! Baking…