Oatmeal cream pies were a favorite treat as a child, usually reserved for something special, like long car rides or birthday parties. It’s been a long time since I’ve eaten one from the grocery store, but I decided it would be appropriate to introduce my own children to their magic. I opted for a swiss meringue buttercream for the filling instead of the usual marshmallow fluff-based inside and ended up liked this grown-up version much better. Letting the filled cookies sit for a few hours before snacking is my favorite way to enjoy.

• 1 cup all-purpose flour
• 3/4 teaspoon baking soda
• 1/2 teaspoon salt
• ¾ teaspoon cinnamon
• 1/4 teaspoon grated nutmeg
• 12 tablespoons (1 1/2 sticks) unsalted butter, room temperature
• 1/3 cup granulated sugar
• 3/4 cup packed brown sugar
• 1 large egg
• 1 tablespoon molasses
• 2 teaspoons pure vanilla extract
• 2 1/4 cups rolled oats

• Adjust an oven rack to the middle position and heat the oven to 350° F. Line three baking sheets with parchment paper.
• In a medium bowl, whisk the flour, baking soda, salt, cinnamon, and nutmeg.
• In the bowl of a stand mixer fitted with a paddle attachment, beat the butter on medium speed until smooth. Add both sugars and beat on medium until light and fluffy, 2 to 3 minutes. Add the egg, molasses, and vanilla and mix on medium until combined. Add the flour mixture and mix on low until just combined. Add the oats and mix on low until combined. Using a spatula, stir the batter to incorporate any stray oats on the bottom of the mixing bowl.
• Form the dough into small balls (about a heaping tablespoon each) and place 12 on each baking sheet. Bake one sheet at a time for 10 to 12 minutes, until the sides are golden brown and the tops are just starting to brown but are still slightly pale.
• Transfer the baking sheet to a wire rack and let cool 5 minutes. Remove the cookies from the pan and let cool completely on a wire rack.

• 4 egg whites
• 1 cup granulated sugar
• ¼ teaspoon salt
• 24 tablespoons (3 sticks) unsalted butter, room temperature
• 1 teaspoon vanilla extract
• 2 tablespoons heavy cream

• In the bowl of a stand mixer, combine the egg whites, sugar, and salt. Put the bowl over a double boiler (set the mixing bowl over a saucepan of simmering water, making sure the bottom of the mixing bowl doesn’t touch the surface of the water).
• Stir the mixture with a rubber spatula until the sugar is completely melted, about 4-5 minutes. While you are stirring, make sure to brush down the sides of the bowl with the spatula –this will ensure that no sugar grains are lurking on the sides, and also will help prevent the egg whites from cooking. Remove the bowl from the heat, and using a whisk attachment, whisk the egg-sugar mixture on medium-high speed until stiff, glossy peaks form, about 8-10 minutes. The bowl should feel just about room temperature. Reduce the speed to medium again, and add the butter, 1 tablespoon at a time, beating well after each addition. When the butter has been completely incorporated, add the vanilla and heavy cream. Beat again until combined. Use immediately.

Fill a pastry bag with the frosting, and then pipe the frosting on the bottom side of one cookie, and top with another. For a softer cookie, let the filled cookies sit for a few hours before enjoying.