Preheat oven to 350 degrees F. Line a cookie tray with parchment paper.
Using a hand mixer or electric mixer, combine the butter, brown sugar, granulated sugar, salt, baking soda, baking powder, and vanilla extract. Mix on low speed for 30 seconds, then on medium speed for another 4 - 5 minutes. The mixture should be light and fluffy.
Add the egg and mix to combine. Add the All Purpose Flour Blend and mix until just combined. Fold in the chocolate chips.
Using a 1 1/2 oz cookie scoop, portion the dough onto a cookie tray prepared with parchment paper, about an inch apart.
Bake for 14 minutes, turning the tray halfway through baking to ensure an even bake. For crunchier, golden brown cookies, add 3 minutes.
Remove from oven and allow to rest on the tray for 5 - 10 minutes.
To begin assembly, place the chocolate chips in a shallow dish.
After the cookies have cooled completely, scoop 1 ounce of allergy friendly sorbet or ice cream onto the bottom of a cookie.
Top with another cookie, and press gently to create a sandwich. The sorbet/ice cream will ideally spread to the outer edge of the cookie.
Gently roll the edge of each sandwich in the chocolate chips. Get an even coating.
Freeze for one hour, until the ice cream is firm.