Preheat oven to 350 F convection.
Sift together (through a strainer) 1 cup + 2 TBL flour, 2/3 cup cocoa and 1/2 tsp baking soda. In a medium saucepan, melt 1–1/2 sticks (3/4 cup) butter. When thoroughly melted, add 1 cup sugar and 1/4 cup corn syrup. Stir and remove from heat. Stir for one minute to help some of the heat dissipate. Add 1 beaten egg. When incorporated, add the dry ingredients. Add 1–1/2 tsp vanilla.
Form into 1–1/4” diameter balls (I have a 1–1/2 tsp scoop that does this), and place onto parchment paper-lined baking sheets. Bake for 11 minutes. Cookies will fall after they come out of oven and form chewy chocolate wafer. Baking them a little longer will produce crisper cookies. Let rest for 2-3 minutes before removing to a rack to cool. Makes about 5 dozen small cookies.
NOTE: the dough will get stiffer the longer it sits and this will change the way the cookies come out. I prefer to work quickly but the cookies are great either way.