Line an 11x7 glass pan with parchment paper. Hold the paper in with binder clips. If you wish to use a larger pan, you will need more cookies!
Line the pan with even rows of cookies, chocolate side UP. I used 12 cookies: 3 across and 4 down. They fit perfectly.
In a medium bowl, combine the sweetened condensed milk, vanilla, and 1/2 cup of chocolate chips. Stir to combine.
Using the whisk attachment, beat two cups of heavy whipping cream until stiff peaks form, about 2 minutes on medium high speed. Be careful not to whip too much or you will make butter.
Fold the whipped cream into the sweetened condensed milk until completely combined.
Spread the ice cream mixture evenly over the cookies. If you use this size pan, you will have extra that you can freeze as ice cream.
Top with an even layer of cookies in the same pattern as those on the bottom. This time, the chocolate will face DOWN.
Cover with aluminum foil and freeze until firm, about 8 hours.
When the ice cream is frozen, lift everything out using the edges of the parchment paper.
Cut into individual sandwiches.
Pour the remaining chocolate chips into a dish. I used a pie plate. Roll the sides of the ice cream sandwiches in the chocolate chips.
Return to the freezer until ready to eat.
Notes
NOTE: Two boxes of Le Petit Ecolier cookies have twelve cookies.