Every October 23, Bostonians, bakers, and dessert aficionados across the country celebrate National Boston Cream Pie Day. But keep in mind when that when you're whipping up your own cake, you might not have the original recipe on hand.

The dessert was first dished out in October 1856 at Boston’s Parker House–a historic hotel on Boston’s Freedom Trail that’s now known as the Omni Parker House. Sold in Parker’s Restaurant, the cake was referred to as “Chocolate Cream Pie.” What distinguished the cake from other restaurant fare was its innovative use of chocolate icing—a rarity at the time, since chocolate was mostly used in drinks and puddings. In any case, the sweet treat became so sought after that it was made into a Betty Crocker boxed mix in 1958, and sold until the 1990s.

In 1996, the Boston Cream Pie was named the official dessert of Massachusetts, cementing its place in our cookbooks—and taste buds—for good. But over time, the recipe has been changed, varied, and replicated by countless bakers. 

You’ve likely encountered a version of Boston Cream Pie that’s similar to a Washington pie, which is a two-layer, jam-filled yellow cake covered with confectioner’s sugar. (In this adaptation, the jam is swapped out for pastry cream.) There are fruit-filled and caramel-drizzled cakes, and you’ve most likely encountered Boston Cream Pie doughnuts, cheesecakes, and yogurts as well. There's even an all-chocolate version by Hershey. But if you're hankering for the real thing, you can scope out the original recipe—which will yield two layers of golden sponge cake separated by pastry cream, covered with chocolate fondant and toasted almonds—over at the Omni Parker House website.

[h/t Omni Hotels]