Brown Butter Shortbread Cookies with Dulce De Leche.

Last weekend I found 4 cans of sweetened condensed milk in the cupboards.  With one of the cans, I decided to make some dulce de leche.  It was super easy (just pour a can into a large microwave-safe bowl, zap for 10-15 minutes on 30% power, stirring every few minutes until it's golden), but left me with a jar of dulce de leche.  So last night I had this genius idea to make some brown butter cookies and sandwich them with the dulce de leche.  Sounds delicious, right?  They were!  However these cookies were almost TOO tender - they crumbled into pieces at the most gentle touch, so they were smashed into bits after this photo shoot and will hopefully make a super crust for something in the future.  I'm going to post the recipe here, maybe someone can tell me what I did wrong?

Brown Butter Shortbread Cookies
Adapted from Blue Ridge Baker who adapted it from Flo Braker
8 tablespoons (1 stick) unsalted butter, browned and cooled
1 cup all-purpose flour
1/4 teaspoon baking soda
1/4 teaspoon kosher salt
1/2 teaspoon vanilla extract
1/2 cup granulated sugar

Sift or whisk the flour, baking soda and salt into a small bowl and set aside.  Transfer the browned butter to a medium bowl and add half the sugar, stirring until it's dissolved, then the other half, then the vanilla extract.  Stir the flour mixture into the butter until everything is combined, then let it rest for 10 minutes so the flour can absorb the butter.

Preheat the oven to 350 degrees F. and line a baking sheet with parchment paper.  Form the dough into small circles or balls and bake until they're golden brown around the edges, 15-25 minutes, depending on how large or small you've made them.

Let cool completely on a wire rack.