In a small bowl place 1/4 cup granulated sugar and 2 Tbsp. softened butter. With a mixer beat until pale and fluffy. Add 1/3 cup finely ground hazelnuts or hazelnut meal; 1 egg yolk; 2 tsp. all-purpose flour; 1/4 tsp. vanilla; a pinch salt; and 1 1/2 tsp. hazelnut liqueur (such as Frangelico), hazelnut extract, or brandy. Mix until completely combined.
To Make Dough in a Food Processor
To make dough in a food processor, pulse two or three times to combine flour, sugar, baking powder, and kosher salt. Add butter and cream cheese; pulse 10 to 15 times or until mixture looks like coarse meal. Add vinegar and 1 1/2 to 2 Tbsp. water; pulse five more times. Turn dough out into a bowl and form into four balls. Wrap individually and chill 1 hour.