How to brown butter for cookies?

Brown butter (or beurre noisette) adds an incredible nutty, caramel flavor to cookies. To make it:

1. Melt unsalted butter in a saucepan over medium heat, stirring constantly
2. After it bubbles, golden particles will appear at the bottom and a nutty aroma will develop
3. Remove from heat immediately when it reaches a golden amber color
4. Cool it and refrigerate until solid before using in your recipe

Use it as a direct replacement for regular butter.