📖 Instructions

1. Before you even think about mixing, take your butter out of the fridge! It needs to soften up for about an hour at room temperature. Trust me, it makes a huge difference in the dough's texture. While that's happening, preheat your oven to 375°F (190°C) and line two large baking sheets with parchment paper. This parchment paper is your best friend for non-stick baking and easy cleanup, seriously.
2. In a medium-sized bowl, whisk together your dry ingredients: the all-purpose flour, baking powder, and salt. Make sure they're really well combined. You don't want a bite of cookie that's super salty and another that's bland, right? Set this bowl aside for a moment.
3. Now, in a much larger mixing bowl, or the bowl of your stand mixer fitted with the paddle attachment, cream together the softened unsalted butter and granulated sugar. Beat them on medium-high speed until the mixture is light, fluffy, and looks pale in color. This usually takes about 2-3 minutes. This step is crucial for incorporating air, which gives your cookies that lovely soft texture.
4. Once the butter and sugar are perfectly creamed, beat in the large egg. Make sure it's fully incorporated before adding the vanilla extract. Scrape down the sides of the bowl with a rubber spatula to ensure everything is mixed evenly. Sometimes bits of butter and sugar cling to the sides, so a good scrape is essential.
5. Gradually add the dry ingredient mixture to the wet ingredients. Mix on low speed until just combined. Be careful not to overmix! Overmixing develops the gluten in the flour too much, which can lead to tough cookies. As soon as you see no more streaks of flour, stop the mixer. Sometimes I even do the last few stirs by hand with a spatula just to be sure.
6. Divide your dough in half, flatten each half into a disk, wrap them tightly in plastic wrap, and pop them into the refrigerator for at least 30 minutes. This chilling step is a non-negotiable, my friends! It helps the butter solidify, preventing the cookies from spreading too much in the oven and ensuring they hold their cute shapes.
7. Once chilled, take one disk of dough out of the fridge (keep the other one chilled!) and place it on a lightly floured surface. Dust your rolling pin with a little flour too. Roll the dough out to about a 1/4-inch thickness. If it's too thin, your cookies might get crispy; too thick, and they won't cook evenly.
8. Now for the fun part! Use your favorite cookie cutters to cut out shapes. Gently transfer the cut-out cookies to your prepared baking sheets, leaving about an inch of space between each cookie. Re-roll any dough scraps, but try not to handle the dough too much. If the dough gets too warm, pop it back in the fridge for 10 minutes.
9. Bake the cookies for 8-11 minutes, or until the edges are very lightly golden. The centers should still look soft and slightly puffy. Remember, ovens vary, so keep an eye on them! You definitely don't want to overbake these, as that's the enemy of a soft cookie.
10. Once baked, let the cookies cool on the baking sheets for about 5 minutes. They're delicate when hot! After 5 minutes, carefully transfer them to a wire cooling rack to cool completely. This is super important before icing; otherwise, your icing will melt and make a mess.
11. While the cookies are cooling, let's whip up that smooth icing! In a medium bowl, whisk together the powdered sugar, 4 tablespoons of milk, and the vanilla extract until smooth. If the icing is too thick, add more milk, a tiny bit (1/2 teaspoon) at a time, until you reach a pourable, yet still thick, consistency. If it's too thin, add a little more powdered sugar. It's all about feel here!
12. Once your cookies are completely cool, spoon the icing over each one, spreading it gently with the back of a spoon or an offset spatula. Immediately after icing each cookie, shower it with your chosen sprinkles before the icing sets. Let the iced cookies sit at room temperature for about 30-60 minutes, or until the icing is set. Then, enjoy your beautiful, yummy creations!