For the cookies

1. Preheat oven to 325 degrees Fahrenheit and line baking sheet with parchment paper or silicone baking mat.
2. Combine flour, cornstarch, baking soda, and salt in medium-sized bowl. Set aside.
3. Mix together melted butter, brown sugar, molasses, egg yolks, and vanilla in large bowl.
4. Add dry ingredients to wet ingredients and stir until mostly combined.
5. Slowly stir in mini chocolate chips.
6. Use a medium-sized (about 2-Tablespoons) cookie scoop to scoop dough and roll into balls. Place dough balls on baking sheet at least 2 inches apart.
7. Bake for 9-12 minutes or until edges are just set but center still looks soft.
8. Remove baking sheet from oven and cool for about 5 minutes before moving to wire rack to cool completely.
9. Once cooled, place baked cookies in freezer for at least 30 minutes before assembly.

For assembly

1. Remove 2 cookies from freezer.
2. Using the same scoop that you used for the cookie dough, place one scoop of ice cream between two cookies and gently press cookies together.
3. Roll sides in mini chocolate chips or sprinkles.
4. Wrap ice cream sandwich in plastic wrap or parchment and return to freezer.
5. Repeat with remaining cookies.
6. Freeze for at least 1 hour. Or place wrapped ice cream sandwiches in sealed freezer-safe bag for up to 3 months.