1. Prepare the Cookie Dough:

• Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper.

• In a medium bowl, whisk together the flour, baking soda, and salt.

• In a separate large bowl, cream together the softened butter and granulated sugar until light and fluffy, about 2-3 minutes.

• Beat in the egg and vanilla extract until well combined.

• Gradually add the dry ingredients to the wet ingredients, mixing just until incorporated.

• If the dough feels too thick, add a tablespoon of milk to soften it slightly.

2. Divide and Color the Dough:

• Divide the dough into small portions, depending on how many colors you want to use. For a typical rainbow swirl, divide into 3-4 portions.

• Add a few drops of neon food coloring to each portion and knead it into the dough until the colors are fully incorporated. (Use gloves or cover your hands as the coloring can stain).

3. Shape the Cookies:

• Roll small balls of each colored dough and place them together on the baking sheet, making sure the colors are touching but not mixed.

• Gently press the dough balls together, then flatten them slightly with the palm of your hand. You should have multi-colored cookie dough mounds.

• Bake in the preheated oven for 8-10 minutes or until the edges are lightly golden. Be careful not to overbake as the cookies should remain soft.

4. Cool the Cookies:

• Allow the cookies to cool completely on a wire rack before assembling the ice cream sandwiches.

5. Prepare the Ice Cream Filling:

• In a bowl, take your softened vanilla ice cream and divide it into separate bowls for each color you want to use.

• Add a few drops of neon food coloring to each bowl and stir well to achieve your desired shades. You can mix multiple colors for a fun swirl effect.

• If you’d like to stabilize the ice cream a bit, mix in a tablespoon of powdered sugar to prevent it from melting too quickly.

6. Assemble the Ice Cream Sandwiches:

• Once the cookies are completely cooled, scoop a generous amount of your neon-colored ice cream onto the flat side of one cookie.

• Place another cookie on top, pressing gently to sandwich the ice cream between them.

• Repeat for all the cookies.

7. Chill the Sandwiches:

• Place the assembled ice cream sandwiches on a baking sheet lined with parchment paper and freeze them for at least 1-2 hours to allow the ice cream to firm up.

8. Serve and Enjoy:

• Once chilled and firm, serve the Glow Swirl Ice Cream Sandwiches. They’ll look even more vibrant when the UV light hits them, making them perfect for a glow-in-the-dark or neon-themed party!