Preheat your oven to 375°F (190°C) and line your baking sheets with silicone liners or parchment paper.

In one bowl, whisk together the flour, salt, and baking soda. Set aside.

In another bowl, use an electric mixer on medium speed to beat the softened butter, granulated sugar, and brown sugar until the mixture is light and fluffy.

Add the egg and vanilla to the butter mixture, mixing well until fully incorporated.

Reduce the mixer speed to low and add the flour mixture, mixing just until combined. Avoid overmixing to ensure tenderness.

Gently fold in the diced peaches and peach preserves until well distributed throughout the dough.

Drop tablespoonfuls of the dough onto the prepared pans, leaving about 2 inches between each cookie.

In a small bowl, combine sanding sugar and cinnamon. Sprinkle each cookie with about 1/8 teaspoon of this mixture for an extra touch of sweetness.

Bake the cookies for 11 to 13 minutes, or until they are golden brown and just set. Be sure to refrigerate any leftover dough between batches.

Allow the cookies to cool on the baking sheets for 5 minutes before carefully transferring them to wire racks to cool completely.