This twist on a classic starts with a large cupcake for one and builds—up or out, as you prefer. The whipped cream adds a fluffy lightness and helps keep the layers stacked. It’s almost too pretty to eat.
For the mini cake: Preheat the oven to 350°F. Use 1 teaspoon of the butter to grease the inside of a 4-inch ramekin. Add 1 teaspoon of the flour, rotating the ramekin to coat it evenly, and shake out the excess.
In a small bowl, whisk the egg white with the brown sugar until the sugar dissolves. Stir in the remaining 1⁄4 cup flour and 2 tablespoons butter, the milk, vanilla, and baking powder, and beat until smooth.
Pour the batter into the prepared ramekin, set it on a baking sheet, and place it in the oven. Bake for 24 to 26 minutes, until the cake is golden on top and a toothpick inserted in the center comes out clean. Set it aside on a rack to cool completely, about 30 minutes.
For the whipped cream: In a medium bowl, whisk the cream until soft peaks form. Add the confectioners’ sugar and whisk gently to combine. Taste and add more confectioners’ sugar, if desired.
Remove the cake from the ramekin and cut it horizontally into two disks of cake of equal size. Place one disk on a dessert plate and top with half of the whipped cream and half of the strawberry slices. Stack the second disk on top and layer it with the remaining whipped cream and strawberries. Serve immediately.