Money No joke! A Peeps doughnut and marshmallow-flavored coffee are coming to Dunkin’ on April 1 March 27, 2019 Kelly Tyko, USA TODAY Comments Off on No joke! A Peeps doughnut and marshmallow-flavored coffee are coming to Dunkin’ on April 1 Dunkin' has a new Peeps Donut and Peeps Marshmallow-flavored coffee coming April 1. The candy brand also a slew of new flavors and a contest.