What do French toast, maple brown sugar oatmeal, and strawberry cheese danish have in common? They’re all popular breakfast foods, but they also share a slightly sweeter distinction: all three have been flavors for Kellogg’s ever-popular Pop-Tarts, the rectangular toaster pastry with the immoveable sprinkles that is marking its 50th birthday this year.

Over the decades, Pop-Tarts have been the source of damage lawsuits, talk show lampoons, and surpassingly weird advertising campaigns, but their popularity continues to grow. Why is a sugar brick with frosting that refuses to melt so appealing? Let’s take a look back.

It all started when the Post cereal company unveiled a breakfast breakthrough called Country Squares late in 1963. The lag time between Post’s announcement of their flat, fruit-filled pastry invention and its attempt to put it on the market allowed rival Kellogg to develop their own version and market it as the Pop-Tart. The original flavors of brown sugar cinnamon, blueberry, strawberry, and apple currant (now defunct) took the market by storm, aided by pure novelty and a perky talking toaster mascot named Milton (who debuted in 1971).

Oddly enough, Kellogg never intended its brainchild to be marketed alongside existing breakfast cereals and products. Grocery store managers starting in 1964 received emphatic instructions stipulating, “IN NO WAY SHOULD THIS PRODUCT BE SOLD AS A SUBSTITUTE FOR CEREAL.”

The Pop-Tart phenomenon grew quietly until the early 1990s, when Thomas Nangle sued the Kellogg company for damages after a tart got stuck and caught fire in his toaster; his case and the sprinkling of lawsuits that followed it inspired the immortal warning that’s still stamped on Pop-Tart boxes today: "Due to possible risk of fire, never leave your toasting appliance or microwave unattended." No kidding. In two independent experiments by humor columnist Dave Barry and Texas A&M professor Patrick R. Michaud, it was discovered that a strawberry Pop-Tart in distress could produce flames over a foot high.

Strawberry filling may have gained notoriety for its flammable properties, but Pop-Tart flavors are startlingly numerous. They range from fruit to nuts to ice cream, and differ depending on the season or country of sale — the Kellogg company also markets the pastries abroad in Canada, Ireland, and the U.K., where flavors have included Strawberry Sensation and Chocotastic. Campy names aren't reserved just for foreign markets, however; American Pop-Tart flavors have included Wild Magic Burst, Guava Mango, French Toast, and Disney Princess Jewelberry (whatever that tastes like—glitter glue, perhaps?). The Pop-Tarts website lists 28 official flavors at present, not including such seasonal favorites as Gingerbread and Choc-o-Lantern Frosted Chocolate Fudge. The three oldest have historically been the most popular.

Somehow, Pop-Tarts have decently weathered the recent debates over advertising and childhood obesity. Kellogg has been forced to remove the phrase “Made with Real Fruit” from the label, but the “Crazy Good” advertising campaign that launched in 2005 has caused sales to balloon in recent years, especially in the market of families with 10-to-12-year-old children. But your hands need not be on the small and sticky side to enjoy ripping open the shining foil packet and popping one in the toaster on a Saturday morning. Nutritionally, we may know better, but pass me a cherry one—here’s to another 50 years, Pop-Tarts.