In a large mixing bowl, whisk together the instant pudding mix and cold milk for 5 minutes, until the pudding is soft-set. Fold in the Cool Whip and set aside.

In an electric stand mixer with the whisk attachment, beat the softened cream cheese and butter on medium-high speed until smooth and creamy, about 30 seconds. Add the powdered sugar and mix on low until combined, then beat again on medium-high until smooth, about another 30 seconds.

Combine the pudding mixture with the cream cheese mixture and mix on medium-high speed until well blended. Use a spatula for further mixing and refrigerate until ready to use.

Process the Oreos in a food processor until fine crumbs are formed, or crush them in a Ziplock bag using a rolling pin or mallet.

In an 8.25? trifle bowl, layer 1/3 of the pudding mixture (about 2-1/2 cups) at the bottom, followed by 1/3 of the cookie crumbs (about 1 cup). Spread each layer evenly.

Repeat the layering process two more times. Alternatively, layer in individual glasses or cups.

Cover the Dirt Cake and chill for at least 12 hours before serving. Top with gummy worms and/or edible flowers as desired.