1. Make the Raspberry Syrup

• In a small saucepan, add 1 cup frozen raspberries and ¼ cup granulated sugar.
• Heat over medium-low heat, stirring frequently until the mixture breaks down and thickens, forming a syrup-like consistency.
• Use a fine mesh strainer to remove seeds and separate the smooth syrup.
• Set aside to cool completely before using in the dough.

2. Cream the Butter and Sugars

• In a large mixing bowl or stand mixer, combine the softened butter, granulated sugar, and light brown sugar.
• Beat on medium-high speed for about 2–3 minutes until the mixture is light and fluffy.
• This step is crucial for incorporating air and creating a soft, chewy texture.

3. Add Milk and Vanilla

• Slowly add ¼ cup dairy-free milk and 1 tablespoon vanilla extract to the creamed mixture.
• Beat until fully combined.
• Scrape down the sides of the bowl to ensure everything is evenly mixed.

4. Mix the Dry Ingredients

• In a separate bowl, whisk together the 2½ cups gluten-free flour, ½ teaspoon baking powder, and ½ teaspoon salt.
• Gradually add the dry ingredients to the wet mixture, mixing on low speed until a dough forms.
• Be careful not to overmix, especially when working with gluten-free flour, to avoid dense cookies.

5. Fold in Chopped Raspberries

• Finely chop ¾ cup of frozen raspberries.
• Gently fold them into the dough using a spatula or wooden spoon.
• Stir just enough to distribute the fruit without overmixing or breaking down the berries.

6. Swirl in Raspberry Syrup

• Add the cooled raspberry syrup to the dough and gently fold it in a few times to create a marbled effect.
• Avoid fully mixing it in, as you want streaks of raspberry visible throughout the dough.

7. Scoop and Shape the Cookies

• Use a cookie scoop or tablespoon to portion out the dough onto the prepared baking sheets.
• Leave about 2 inches between each cookie to allow for spreading.
• If desired, slightly flatten the tops for a more uniform shape.

8. Bake the Cookies

• Place the cookies in the preheated oven and bake for 15–17 minutes.
• The edges should be set, and the centers may look slightly soft, which is perfect.
• Do not overbake, as these cookies will continue to set as they cool.

9. Cool and Enjoy

• Let the cookies rest on the baking sheet for 5 minutes before transferring them to a wire rack.
• Once completely cooled, store in an airtight container for up to 5 days.