Favourite Whoopie Pies

Whoopie pies are the great Pennsylvania Dutch / New England lunchbox dessert: two soft, cake-like chocolate rounds wrapped around a thick layer of marshmallow buttercream filling. The cakes here use a clever trick from old Amish bakers, dissolving cocoa in hot water before mixing it into the batter, which deepens the chocolate flavor and gives the cakes a moist, almost devil’s-food crumb.

Sour milk reacts with the baking soda for extra lift, so the cakes bake up tall and pillowy rather than flat and dense. The filling is a quick whip of shortening, marshmallow cream, powdered sugar, and vanilla. It tastes like the inside of a homemade Twinkie and stays soft even when chilled, which matters because these freeze beautifully.

Pro Tips

• Drop batter by rounded teaspoonfuls and leave plenty of space; whoopie pies spread to almost three times their size in the oven.
• Match cake sizes when sandwiching. Sort the rounds into pairs by diameter before filling so you don’t end up with lopsided pies.
• If you don’t have sour milk, stir 1½ teaspoons of lemon juice or white vinegar into half a cup of regular milk and let it sit for 5 minutes.
• Wrap individually in plastic wrap before freezing. Eat them straight from the freezer, the filling stays soft and they’re like ice cream sandwiches.

Variations

• Use butter instead of shortening in the filling for a richer, more buttercream-like flavor (though they won’t keep at room temp as well).
• Swap the chocolate cakes for pumpkin spice cakes in the fall, with a cream cheese filling.
• Add a layer of raspberry jam under the marshmallow filling for a chocolate-raspberry variation.