Crumbl is getting festive for the start of spring and upcoming holidays with a St. Patrick's Day and Pi Day lineup for the week of March 11-16.

In honor of Pi Day on Thursday, March 14, all Crumbl locations will offer a special pie-themed Mystery Cookie flavor. As is the nature of the Mystery Cookie, each Crumbl location will pick their Mystery Cookie’s flavor, which can change throughout the week, and every store will offer something different.

Available as the sixth menu item for the full week, this Mystery Cookie theme pays homage to the mathematical marvel while offering a unique twist on the classic cookie experience.

With St. Patrick's Day approaching on Sunday, March 17, Crumbl is also rolling out a celebratory lineup of themed cookies, available from March 11-16. The festive flavors include Mallow Creme ft. Lucky Charms, Coconut Lime, Buttermilk Pancake, Mint Brownie Batter and Milk Chocolate Chip.

Customers are encouraged to grab their cookies ahead of time as stores are closed on Sundays, and this year, St. Patrick's Day falls on a Sunday.