Preheat oven to 350°F, line baking sheet.
Beat butter, sugar until creamy using hand mixer.
Add egg, vanilla, beat until combined.
Mix flour, baking powder, salt in bowl.
Add dry ingredients to butter, mix until dough forms.
Scoop Nutella into small frozen scoops.
Scoop cookie dough, flatten with fingers.
Place Nutella in center of dough.
Wrap dough around Nutella, seal edges well.
Roll balls in sugar for crisp coating.
Place on baking sheet, spaced evenly apart.
Bake for 10-12 minutes until edges turn golden.
Cool on rack before serving or storing.