whisk flour, soda and salt in small bowl (photo 1)
combine chocolate, sugars and cocoa in a food processor, and pulse and chop until powdery (photo 2)
add butter to the chocolate mixture and process until combined
add eggs and vanilla to the chocolate mixture and process until combined
turn the chocolate mixture into a bowl, stir in the flour mixture and mix until all the flour is incorporated (the dough will be very stiff, like gingerbread dough)
cover the bowl with plastic wrap and refrigerate until firm (at least one hour)
alternatively, you can form the dough into logs with waxed paper and slice the logs into rounds when chilled
roll the dough into 1” balls (photo 3)
and then roll in icing sugar or granulated sugar (photo 4 and 5)
place balls on parchment-lined baking sheet but don’t flatten them (they will spread by themselves)
bake cookies on middle rack of oven for about 10 minutes until set but centre looks underdone
cool cookies in pan for a couple of minutes and then transfer to a wire rack to completely (photo 6 and 7)
hide the cookie tin from your family
Recipe by You Have Been Served at https://www.youhavebeenserved.ca/2015/04/10/chocolate-crackle-cookies/