Moon Pies

1. Stage

Into a large bowl, sift flour and cocoa powder. Add salt and baking soda, then whisk to combine.

2. Stage

In the large bowl of a stand mixer fitted with the paddle attachment, beat butter and granulated sugar until fluffy and pale, 3 minutes. Add egg and vanilla and beat until combined, about 1 minute more. (If the mixture starts to look separated, continue to beat until it resembles thick cake batter, about 1 minute more.)

3. Stage

Reduce mixer speed to low and add dry ingredients, one big spoonful at a time. Beat until dough comes together in large clumps. Be careful not to overmix. If there’s still flour at bottom of bowl, fold to incorporate with a spatula.

4. Stage

On a clean work surface, form dough into a ball. Divide into 2 pieces. Roll one half of dough between 2 (14"-long) pieces of parchment to 1/2" thick. Slide onto a baking sheet and refrigerate until firm, about 30 minutes. Repeat with remaining dough.

5. Stage

Preheat oven to 350° and line a baking sheet with parchment. Starting with first sheet of dough, punch out rounds with a 2 3/4"-round cookie cutter and place on prepared sheet. Roll scraps and repeat until all dough is used. Repeat with remaining dough sheet. Refrigerate until chilled, about 15 minutes.

6. Stage

Bake cookies until cookies appear dry around the edges, 10 to 12 minutes. Let cool on baking sheet. Gently slide parchment and cookies onto a wire rack and let cool completely.

7. Stage

Place 2 tablespoons cold water in a small bowl and sprinkle with gelatin. Using a fork, quickly mix to combine so no clumps form; the gelatin will absorb water and gel fast.

8. Stage

In the large bowl of stand mixer fitted with the whisk attachment, beat egg whites on low speed.

9. Stage

Meanwhile, in a small saucepan over medium heat, cook granulated sugar, corn syrup, and 1/2 cup water until an instant-read thermometer registers 241° about 15 minutes total. Note: After about 5 minutes, you will see tiny bubbles simmering under surface of water, trying to erupt. The bubbles will then form around edge of saucepan at around 6 minutes, and those bubbles will start dancing around, trying to make their way to center of pan at around 7 minutes. The syrup will start bubbling more aggressively, and the tiny bubbles that were trapped underneath will break their way to surface. By 10 minutes, bubbles will be only on surface, and eventually, they will take longer and longer to pop. By 15 minutes, there will be bubbles all over, some big and some small, and some defiantly holding their shape. At this point, crank up speed on mixer to high. The egg whites should be just starting to form peaks as sugar syrup registers 244°.

10. Stage

Scoop gelatin into a small saucepan. Heat on lowest setting just until gelatin melts, which happens quickly.

11. Stage

Slowly pour sugar syrup into egg whites by setting pot along lip of bowl and drizzling on side of bowl so it doesn’t splash and beat to combine. Pour in melted gelatin (if it has solidified, return to stove over lowest heat until it melts) and continue to beat on high speed 1 minute. Add vanilla. Reduce mixer speed to medium and continue to beat until mixture cools slightly so bowl isn’t hot to the touch, 4 to 5 minutes.

12. Stage

Immediately transfer marshmallow filling to a piping bag fitted with a large tip (such as Wilton 2A) to prevent it from setting. (If you don’t have a piping bag, no problem—you can fill cookies with a spoon.)

13. Stage

Arrange half of cookies on a work surface. Pipe or spoon a mound of filling (about 2 tablespoons) onto center of cookies. Let sit undisturbed until filling starts to set, about 15 minutes. (If using store-bought marshmallow creme, freeze cookies to firm up.)

14. Stage

Place remaining cookies over filling (don’t press—the weight of the cookie is enough to sandwich it). Let sit at room temperature 3 hours.

15. Stage

Meanwhile, in a large heatproof bowl, microwave chocolate and oil in 30-second increments, stirring between each, until melted and smooth.

16. Stage

Place cookies on a wire rack set inside a baking sheet. Spoon melted chocolate over cookies and coax down sides with the back of a spoon. Let set 30 minutes.

17. Stage

Using a butter knife, remove moon pies from rack and transfer to a platter.