Lemon Ice Cream Sandwiches with Blueberry Swirl
- 2 pints vanilla ice cream
- 1 tablespoon grated lemon zest
- 2 tablespoons fresh lemon juice
For blueberry compote:
- 2 cups blueberries (10 ounces)
- 1/4 cup sugar
- 2 (3-by 2 1/2-inch) strips lemon zest
- 1 tablespoon fresh lemon juice
- 2 teaspoons cornstarch
For sandwich layers:
- 1 cup all-purpose flour
- 1/2 teaspoon baking powder
- 1/4 teaspoon baking soda
- 1/4 teaspoon salt
- 1 stick unsalted butter, softened
- 3/4 cup packed light brown sugar
- 1 large egg
- 1/2 teaspoon pure vanilla extract
Make blueberry compote:
Cook blueberries, sugar, and zest in a 12-inch heavy skillet over medium-high heat, thoroughly crushing blueberries with a potato masher (or fork), until juices are released and sugar has dissolved, about 2 minutes.
Stir together lemon juice and cornstarch, then stir into blueberry mixture. Boil, stirring, 1 minute (mixture will thicken).
Transfer blueberry compote to a bowl and chill until cold, about 1 hour. Discard lemon zest.
Make sandwich layers:
Preheat oven to 375°F with rack in middle. Butter a 9 x 13 baking pan and line with foil, leaving a 1-inch overhang on each side, then butter foil. (The original recipe calls for using two 8 x 8 pans, but I only have one, so that wasn’t going to work. I found that using one 9 x 13 worked great, and I only had to clean one pan, instead of two!)
Whisk together flour, baking powder, baking soda, and salt in a small bowl. Beat together butter and brown sugar in another bowl with an electric mixer at medium-high speed until pale and fluffy, about 3 minutes. Beat in egg and vanilla. At low speed, add flour mixture in 2 batches, mixing until just combined.
Divide batter between baking pan(s) and spread into thin, even layers with offset spatula. Bake until golden-brown but still tender, 10 to 12 minutes. Cool completely in pan(s), about 30 minutes. If you used one 9 x 13 pan, once the cake is completely cooled, cut in half to make two even pieces of cake.
Make Lemon ice cream:
Transfer ice cream to a microwave-safe bowl and microwave at 30 percent power in 10-second intervals, stirring, until softened, about 50 seconds total. (Or, if you’re patient, let the ice cream soften at room temperature.) Stir in lemon zest and juice. If it’s too soft for assembling the sandwiches, put it back in the freezer for a while to firm up.
Spoon ice cream over 1 sandwich layer (in pan) and spread evenly using clean offset spatula. Dollop blueberry compote over ice cream, then swirl is gently through the ice cream using a spoon or butter knife. Invert second sandwich layer over ice cream, pressing gently to form an even sandwich. Wrap baking pan in plastic wrap or foil and freeze until firm, at least 2 hours.
Transfer sandwich to a cutting board using overhang. Trim edges if desired, then cut into 8 pieces.