Note: this dough requires chilling!
Melt butter in a microwave safe bowl. Pour into an electric mixer fitted with paddle attachment. While still hot, add both sugars and mix on low until combined. Add ice cream and mix until smooth.
Add egg and vanilla extract, mix for just a few seconds, then add baking soda and salt. Mix until smooth, then mix in flour slowly. Mix dough just until it comes together, then stir in chocolate chips.
Scoop 2 tablespoon balls of dough onto a cookie sheet covered with wax paper. You’re going to chill the dough balls so there is no need to space them out. Cover with plastic wrap and chill for at least 1 hour.
Preheat oven to 350°F. Place cookies 2” apart on cookie sheets covered with parchment paper or silpat baking mats. (If you've chilled them longer than 4 hours you might want to press them down slightly with the palm of your hand otherwise they won't flatten totally.) Bake for about 9-11 minutes, until they start to get golden around the edges. Cool at least 5 minutes on cookie sheets before moving to a rack to cool completely.
Cookies can be stored in an airtight container for up to 4 days or frozen for up to 1 month.