In a medium saucepan, melt 2 sticks of salted butter over medium heat, stirring occasionally. Watch as the butter foams and turns a rich amber brown, releasing a warm, nutty aroma—this should take about 5-8 minutes. Once browned, quickly transfer the butter to a heatproof bowl and let it cool slightly.

In the bowl with the cooled brown butter, add equal parts granulated and brown sugar, whisking until combined and creamy. Crack in 2 large eggs and pour in 1 tablespoon of vanilla bean paste. Whisk vigorously until smooth and glossy.

In a separate bowl, whisk together 2 ½ cups of all-purpose flour, 1 teaspoon of baking powder, and ½ teaspoon of baking soda. Gradually mix this dry blend into your wet ingredients, stirring gently until a thick dough forms.

Using a cookie scoop or tablespoon, portion out the cookie dough and roll into balls. Place on a parchment-lined baking sheet and refrigerate for at least 30 minutes.

Preheat your oven to 350°F (175°C). Once chilled, slightly flatten the balls and place them on the baking sheet, ensuring they are spaced about 1.5 inches apart. Bake for 8-10 minutes, or until edges are golden but centers remain soft.

In a mixing bowl, beat ½ cup of softened butter until creamy. Gradually add in 2 cups of powdered sugar, blending in a splash of milk and 1 teaspoon of vanilla extract. Adjust milk for desired consistency.

Once cooled, frost each cookie with the buttercream and sprinkle colorful decorations on top.