Strawberry Shortcake Sheet Cake is golden, biscuit-style shortcake baked in a sheet pan, topped with juicy macerated strawberries and a rich cream cheese whipped topping. It looks stunning on the table and comes together with simple, from-scratch ingredients. Perfect for Mother's Day, Memorial Day, or any spring and summer gathering.
Hull 1 pound of the fresh strawberries, and cut in half lengthwise; set aside. Hull and chop strawberries from the remaining 1 pound of berries to measure 1 cup; set aside. (Reserve remaining whole berries for another use.)
Preheat oven to 400°F. Coat a 13- x 9-inch rimmed baking sheet with cooking spray. Whisk together self-rising flour, all-purpose flour, salt, and ½ cup of the granulated sugar in a large bowl. Cut cold butter cubes into the flour mixture until butter pieces are evenly coated and pea-sized. Gently fold in buttermilk, lemon zest, ⅔ cup of the whipping cream, and 1 teaspoon of the vanilla until the mixture just comes together but is still lumpy. Gently fold in the reserved chopped strawberries.
Using a ¼-cup measuring cup dusted with all-purpose flour to prevent sticking, scoop slightly rounded dough mounds onto prepared baking sheet in 3 rows of 6 side-by-side mounds, continuing to flour scoop after each mound to prevent sticking. Brush dough mounds evenly with melted butter, and sprinkle with sanding sugar. Bake in preheated oven until golden brown, 28 to 32 minutes. Transfer baking sheet with shortcake to a wire rack, and cool 10 minutes. Transfer shortcake to wire rack; cool completely, about 1 hour.
Meanwhile, stir together halved strawberries and remaining ¼ cup granulated sugar in a medium bowl, and let stand until berries start to release their juices, 10 to 15 minutes.
Gently mix together (I use a hand mixer on low) the cream cheese, powdered sugar, and remaining 2 teaspoons vanilla in a separate medium bowl until just combined. Pour remaining 1 cup whipping cream into a separate large bowl, and beat with an electric mixer fitted with a whisk attachment on high speed until stiff peaks form, 2 to 3 minutes. Gently fold whipped cream into the cream cheese mixture until just combine.
Spread whipped cream-mascarpone mixture over top of cooled shortcake, leaving edges exposed. Top with strawberry mixture and any accumulated juices. Slice evenly into 12 pieces, and serve immediately.