Directions

1. Beat the butter, chocolate-hazelnut spread, white sugar, and brown sugar with an electric mixer in a large bowl until smooth. Blend the whole egg into the butter mixture. Beat in the egg yolk and vanilla.
2. In a separate bowl, sift together the flour, baking soda, and salt. Mix the dry mixture into the egg and sugar mixture about 1/3 at a time until all the flour is incorporated. Gather the dough into a ball and wrap in plastic wrap. Refrigerate at least 30 minutes.
3. Preheat an oven to 400 degrees F (200 degrees C).
4. Roll dough into large balls (about the size of a golf ball) and place 2 inches apart on ungreased cookie sheet. Bake until cookie is slightly firm on the outside, 8 to 10 minutes. Cool cookies on pans before removing.