PREHEAT oven to 350F. Line 2 baking sheets with parchment.
WHISK flour, cocoa, baking soda and salt in a bowl.
BEAT butter and both sugars in a large bowl using an electric mixer on medium until fluffy, about 3 min. Add egg and beat for 1 min, scraping sides and bottom of bowl. Add Nutella and vanilla and beat until smooth. Beat in flour mixture on low until just combined.
SCOOP out 2-tsp portions of dough and roll into balls. Place 16 cookies 1 in. apart on a prepared sheet. Bake until puffed and slightly cracked on top, about 5 min. Let cool for 1 min, then transfer to a rack to cool. Repeat with remaining dough.
FROSTING: Beat butter and Nutella in a large bowl with an electric mixer on medium-high until fluffy, 2 min. Add icing sugar and salt and beat on medium-low until well combined. Increase speed to medium and beat until light, 1 min. Add milk and beat for 2 min. Transfer to a piping bag fitted with a small star tip.
FLIP half of the cookies and pipe about 1 tbsp frosting onto each, then top with remaining cookies.
St. Joseph Communications uses cookies for personalization, to customize its online advertisements, and for other purposes. Learn more or change your cookie preferences. By continuing to use our service, you agree to our use of cookies.
We use cookies (why?) You can change cookie preferences. Continued site use signifies consent.