Trademark Tarts is giving Bostonians a reason to get out of bed early on weekends. Saturday and Sunday mornings, self-taught baker Justin Burke-Samson, 30, is popping up at Boston-area restaurants with his reimagined Pop-Tarts ($3) in flavors such as mocha coconut and Key lime pie. “I love the idea of revamping something from childhood into something finer,” he says. The venture is playfully named to avoid trademark infringement. Burke-Samson’s day job is development director for the nonprofit Mass Farmers Markets, but he’s had a passion for baking since he was a teen. Proceeds from his weekend baking go toward a baby fund he and his husband, David Samson, launched to help them cover the costs of starting a family. Last winter Burke-Samson reconnected with friend Stephanie Cmar, a former “Top Chef” contestant, who had just started popping up with her own Stacked Donuts. Cmar asked him to join her, forming a baking duo they’ve dubbed “The Breakfast Club.” The pair has developed an avid following. Lines start forming an hour before doors open and shelves are bare in 30 minutes. Pop out of bed early if you want these tarts. Go to @trademarktarts for locations, times, and flavors.