Brown the Butter: Melt the butter in a small saucepan over medium heat until nutty and golden brown flecks appear. Immediately pour into a mixing bowl and cool for 5–10 minutes.
Whisk Dry Ingredients: In a separate bowl, whisk together flour, cornstarch, baking soda, and salt.
190 g all-purpose flour, 15 g corn starch, 1/2 tsp baking soda, 1/4 tsp fine sea salt
Mix Wet Ingredients: To the browned butter, add granulated sugar, brown sugar, vanilla, and milk. Stir until smooth and glossy.
140 g butter, 100 g granulated sugar, 25 g light brown sugar, 1 tbsp whole milk, 1 tbsp vanilla extract
Combine: Add the dry ingredients to the wet and mix until a stiff dough forms. It will look crumbly at first—just keep mixing. If it’s too dry, add ½ tsp more milk.
Shape & Bake: Preheat oven to 175°C (350°F). Line a baking sheet with parchment. Roll into small 1-teaspoon balls, place 2 inches apart, and press each one flat. Bake for 12–14 minutes until edges are golden and centers are just set.
Cool Completely: Transfer cookies to a wire rack and let cool fully. They will crisp up as they cool.