Preheat your oven to 350°F (175°C). While the oven warms up, we'll prepare our dough.

In a large mixing bowl, beat the softened butter and granulated white sugar together until light and fluffy. I usually start with a hand mixer for even incorporation; it makes the job easier. This step is crucial for incorporating air into the mixture, leading to light cookies.

Once your butter and sugar are well combined, add in that large egg, vanilla extract, and optional almond extract. Beat it until everything is well mixed and smooth. The mixture should look creamy and homogenous.

Now, stir in the freshly grated lemon zest and milk if you're using it. The lemon zest can be transformative—its fresh notes lend depth to the overall flavor.

In another bowl, whisk together the all-purpose flour, baking powder, and sea salt. This step ensures that the leavening agent and salt are evenly distributed before being incorporated.

Slowly add the dry ingredients to the wet mixture. I find it helpful to do this in two or three batches, mixing each thoroughly before adding more. Avoid overmixing; you don’t want tough cookies.

If you have time, let the dough chill in the refrigerator for about 30 minutes. Chilling will firm up the butter, helping your cookies maintain their shape while baking.

Line your baking sheet with parchment paper. Flour your working surface lightly. Scoop the dough into balls—about 1.5 inches in diameter. Roll them in your hands to make them perfectly round.

Place the cookie dough balls on your prepared baking sheet, spacing them about 2 inches apart. Here’s where it gets fun: flatten them slightly with a glass or your hand and decorate with sprinkles or sanding sugar.

Bake in your preheated oven for 8-10 minutes, or until the edges are just lightly golden. The centers will look soft; that’s okay! They’ll continue to set as they cool.

Let the cookies cool on the baking sheet for a few minutes before transferring them to a wire rack. They will firm up as they cool.