adapted from: 101 Gourmet Cookies
2 sticks butter, softened
1 c. sugar
3 egg yolks
pinch of salt
1 1/2 tsp. baking soda
1 1/2 tsp. vanilla
2 1/3 c. all-purpose flour
Cream together butter and sugar until light and fluffy. Add eggs yolks and salt. Beat until well blended. Mix in soda and vanilla. Last, add flour and mix until combined. Cover bowl with plastic wrap and refrigerate for one hour. Form into balls and dip tops in sugar. Place on a lightly greased cookie sheet and flatten cookies using the bottom of a glass. Bake at 350 degrees for 8-10 minutes or until lightly golden. Cool completely and top with frosting.
Browned Butter Frosting
1 stick butter
4 c. powdered sugar
1 tsp. vanilla
1/2 c. heavy cream (I used half-and-half)
Heat butter in a small saucepan over medium heat until golden brown specks appear, stirring occasionally. Butter will get foamy and if you swirl the pan around, the butter will be light brown and you will see brown bits. It will have an amazing nutty smell to it. Almost like english toffee. Remove from heat and cool completely. (I let mine cool slightly, then I put it in the fridge to continue cooling - it might solidify, but that's okay, just use a rubber scraper and scrape every last bit into your mixing bowl). Add powdered sugar and vanilla to mixing bowl with butter. Beat until crumbly. Slowly add cream until frosting reaches desired consistency. Spread onto cooled cookies. Keep refrigerated.
Jenn's Notes: My first batch, I tried a small ice cream scoop for shaping my cookies, but I thought they turned out too big, because they spread out a lot during baking. I shaped the remaining dough into smaller balls. I ended up with 36 cookies (with one large batch and two smaller batches). I liked them best baked for 9 minutes. The cookie is crispy on the outside, but chewy in the middle. The cookies are great, but the frosting is really the star!! It was a good thing I had planned to take these to work or none of the frosting would have made it to the cookies. These cookies are very rich!