01 -
Set your oven to 350°F (175°C). Put parchment on two cookie sheets.
02 -
Beat butter and white sugar together in a big bowl until fluffy and pale. Add the vanilla and mix it in.
03 -
Mix flour, cocoa, and salt in another bowl with a whisk.
04 -
Slowly add your dry mix to the butter blend, stirring until you get a firm, workable dough.
05 -
Make 1-inch balls from the dough. Roll them in the crushed hazelnuts. Put them on your lined sheets about 2 inches from each other.
06 -
Push your thumb or a spoon into each ball to make a little hole.
07 -
Stick them in the oven for 12-14 minutes until they're done but still a bit soft.
08 -
While they're still warm, push down any holes that puffed up. Put a spoonful of nutella in each hole. Pop a whole hazelnut on top if you want it fancy.
09 -
Let them sit on the baking sheets for 5 minutes, then move them to a wire rack until totally cool.