Strawberry-Elderflower Cake

It’s airy, light, and sweet, but this delicate cake gets pucker and punch from vinegar in both the icing and the filling. Step 1 Preheat oven to 350°. Butter a 9”-diameter cake pan and sprinkle with granulated sugar. Whisk flour and salt in a small bowl; set aside. Step 2 Whisk eggs and 1 cup …