Line an 8×8-inch baking dish with

Gefen Parchment Paper. Leave an inch or two hanging over the edges to make it easy to remove the bars from the dish.

In a food processor, pulse the 18 cookies into fine crumbs (do not remove the cream fillings). Add melted margarine and lemon juice and pulse to combine. Press mixture along the bottom of the prepared dish and set aside.

In the food processor, pulse the 15

cookies until they become coarse crumbs. Transfer to a bowl and add margarine, lemon juice, and lemon zest, mixing gently by hand. Transfer to the fridge.

Remove ice cream and sorbet from the freezer and let defrost slightly, 25–35 minutes. Scoop out half the ice cream and use a spatula to spread it in an even layer over the crust. Freeze for 15 minutes or until firm.

Spread all of the lemon sorbet over the ice cream. Freeze for 15 minutes or until firm.

Spread the second half of the ice cream in an even layer over the sorbet. Sprinkle the crumb topping over the top.

Freeze four more hours or overnight. Slice into squares and serve.