In a medium saucepan, combine the strawberries and sugar over medium heat. Stir frequently until the mixture is thick and syrupy, about 10 minutes. It’s okay if it’s still a bit chunky! Strain through a mesh colander into a bowl to remove the seeds and set aside to cool.

In a large bowl, whisk together the gluten-free flour, 1.5 tablespoons of cornstarch, baking powder, and kosher salt. Set aside.

In a small bowl, mix 2 heaping tablespoons of cornstarch with 3 tablespoons of water. Stir until thin and watery (it will be thick and sticky at first — keep stirring!). This acts as the egg substitute to bind the cookies.

Using a stand mixer fitted with the paddle attachment or a handheld mixer, beat the butter (or vegan baking stick) with the 1 ¼ cups granulated sugar until soft, fluffy, and light in color, about 2–3 minutes.

Slowly beat in the cornstarch-water mixture, vanilla extract, milk, and 3.5 tablespoons of the cooled strawberry syrup. The mixture will look pale pink and a bit chunky, which is perfect.

Gradually mix the dry ingredients into the wet ingredients on low speed, mixing until just combined. If you’d like a brighter pink color, add the optional red food coloring and mix briefly to incorporate.

Cover the dough with plastic wrap and refrigerate for at least 2.5 hours, or ideally overnight. This step is essential to prevent the cookies from overspreading.

After chilling, preheat your oven to 325°F (160°C) and line a baking sheet with parchment paper. Scoop 12 evenly sized cookie dough balls using a cookie scoop or ice cream scoop. Roll each dough ball in the reserved 2 tablespoons of sugar.

Place the cookies 3–4 inches apart on the baking sheet (they’ll spread a bit). Bake for about 15 minutes until the edges are set and the centers look slightly underdone — they will firm up as they cool.

As soon as the cookies come out of the oven, use a spatula to gently push the edges into a circular shape if needed. Let them cool on the baking sheet for 5 minutes before transferring to a cooling rack.