Pulse the whole cookies, filling included, in a food processor for 10 to 15 seconds. You want crumbs like coarse potting soil, with a few pea-sized bits left for texture. Without a processor, seal the cookies in a zip-top bag and roll over them with a rolling pin. Measure out about 4 cups of crumbs.

In a large bowl, beat the softened butter and cream cheese with a hand mixer on medium for 1 minute. Add the powdered sugar, vanilla, and salt. Beat 2 more minutes until the mixture is smooth, fluffy, and pale, with no streaks or lumps. Cold cream cheese is the usual cause of lumps, so let it sit out for at least 45 minutes first.

In a second bowl, whisk the pudding mixes with the cold milk for 2 minutes, until noticeably thick. Let it rest 5 minutes to finish setting. Fold the cream cheese mixture into the pudding in three additions with a spatula. Then fold in the whipped topping until no white streaks remain. Don't use the mixer here, because the filling will deflate.

Use 12 clear 8-ounce cups so the layers show. Spoon about 2 tablespoons of crumbs into each cup, then about 1/3 cup of filling. Repeat once, then finish with a generous 2 tablespoons of crumbs. Gently press each crumb layer with the back of a spoon so it holds together. Wipe the inside rims with a paper towel for clean edges.

Cover and refrigerate for at least 2 hours. The filling should feel set and spoonable, not runny. Just before serving, push gummy worms into the crumbs so they look like they're crawling out of the soil, and add a mint sprig as a "plant." Rebecca's Tip: Keep the final layer of crumbs and the gummy worms off until just before serving. Crumbs left under refrigeration absorb moisture from the filling and turn soft and pasty. Adding them at the last minute keeps the "soil" crunchy.