This large format Pop-Tart is the best thing since... Pop-Tarts! Strawberry jam is sandwiched between two pieces of shortbread. The whole thing is glazed and sprinkled with crushed freeze-dried strawberries. —Riley Wofford
all-purpose flour, plus more for rolling
1 1/3 cups
confectioners' sugar, divided
(1 stick) unsalted butter, room temperature
Make dough: place flour, 1/3 cup confectioners' sugar, and salt in the bowl of a stand mixer fitted with the paddle attachment; mix for a few seconds to combine. Add butter and egg; mix on low speed until dough begins to clump together. Transfer to a floured piece of parchment paper. Dust lightly with more flour and top with a second piece of parchment.
Roll dough into an approximate 9-by-16-inch rectangle. Remove top layer of parchment; cut dough crosswise into two 8-by-9-inch pieces and separate slightly. Transfer dough, with parchment, to a baking sheet. Prick all over with the tines of a fork; freeze 10 minutes.
Preheat oven to 350°F. Bake until just set and lightly browned around the edges, 15 to 18 minutes. Let cool completely on pan.
Make icing: in a small bowl, whisk together remaining 1 cup confectioners' sugar, lemon juice, and 1 tablespoon water until smooth. If icing is too thick, add more water, 1 teaspoon at a time, until thin but spreadable.
Spread jam evenly over one half of dough; place other half on top. Drizzle with icing and sprinkle with freeze-dried strawberries. Let stand until icing sets, about 30 minutes. Cut into squares and serve.