Prepare the cookies: Preheat your oven to 350°F (175°C). In a large mixing bowl, cream together the softened butter and granulated sugar until light and fluffy. Add the egg and vanilla extract, mixing until well combined.

1. Mix the dry ingredients: In another bowl, whisk together the flour, baking soda, and salt. Gradually add the dry ingredients to the wet mixture, mixing until the dough comes together.
2. Shape the cookies: Scoop tablespoon-sized portions of cookie dough and roll them into balls. Place the dough balls onto a parchment-lined baking sheet, spacing them about 2 inches apart. Flatten each ball slightly with the back of a spoon or your fingers.
3. Bake the cookies: Bake for 10-12 minutes or until the edges are golden brown. Let the cookies cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.
4. Assemble the sandwiches: Once the cookies have cooled, take a scoop of ice cream and place it between two cookies. Gently press them together to flatten the ice cream slightly. Roll the edges of the ice cream sandwich in sprinkles, mini chocolate chips, crushed nuts, or shredded coconut for extra fun and texture.
5. Freeze the sandwiches: Place the assembled ice cream sandwiches on a baking sheet lined with parchment paper and freeze them for at least 1 hour or until the ice cream is firm.
6. Serve: Once frozen, serve the ice cream sandwiches and enjoy!