01 -
Take half a cup of butter and place it in a small saucepan. Heat it over medium temperature until it melts completely, then let it bubble and foam for about 2 minutes while stirring frequently. This creates a nutty aroma. Remove from heat and set aside.
02 -
In your mixing bowl, combine the remaining softened butter with the browned butter and all the dark brown sugar. Beat this mixture for 4-5 minutes until it becomes smooth and has a beautiful glossy appearance.
03 -
Beat in the whole egg, egg yolk, and vanilla extract, mixing for another minute until everything is well incorporated.
04 -
Gently fold in the flour, baking soda, and salt until just combined. Don't overmix the dough.
05 -
Cover your cookie dough and refrigerate it for 15-30 minutes. This helps the cookies hold their shape and prevents spreading.
06 -
Preheat your oven to 350°F. Put your rolling sugar in a shallow bowl. Shape the chilled dough into golf ball-sized portions, roll each one in the sugar, and place them on light-colored baking sheets with plenty of space between each cookie.
07 -
Bake for 10-12 minutes, watching carefully. The cookies should look slightly underbaked when you remove them - they'll continue cooking on the hot pan and firm up as they cool.