To make the cake: Coat 2 (9-inch) round cake pans with cooking spray; line the bottoms of the pans with wax paper. Coat wax paper with cooking spray; set aside.
Place the sugar and the butter in a large bowl; beat with a mixer at medium speed for 5 minutes or until very well-blended. Add the eggs, 1 at a time, beating well after each addition. Add the vanilla extract.
Lightly spoon the flour into dry measuring cups; level with a knife. Combine the flour, the baking powder, and 1/4 teaspoon salt, stirring with a whisk. Add the flour mixture and the milk alternately to sugar mixture, beginning and ending with the flour mixture; mix after each addition. Pour batter into the prepared cake pans. Sharply tap pans once on counter to remove air bubbles.
Bake at 350° for 30–35 minutes or until a wooden pick inserted in the center comes out clean. Cool cake in pans for 10 minutes on a wire rack; invert pans. Carefully peel off wax paper, and cool cake completely on wire rack. Cake can be made a day in advance and covered in plastic wrap.
Top with Italian-Meringue Icing—check out our step-by-step recipe and decorating tips below.
Step 1: In a large bowl, beat 1/4 teaspoon cream of tartar and 3 large egg whites with a mixer at high speed until soft peaks form. Combine 1 cup sugar, 1/4 cup water, and 1/4 teaspoon salt in a small saucepan. Cook over medium heat, stirring just until sugar dissolves, and bring to a boil. Cook, without stirring, for 2 minutes or until a candy thermometer registers 238°. Pour hot sugar syrup in a thin stream over egg whites, beating at high speed until stiff peaks form. Beat in 1/2 teaspoon vanilla extract.
Step 2: Place 1 cake layer on a cake stand; spread first layer with 1/2 cup icing. Turn the remaining layer upside down (so flat side faces up) and place on top of the first layer. Spread 1/2 cup icing on second layer.
Step 3: Spread remaining icing to cover cake. Create decorative peaks using the back of a large spoon, if desired. You can make cake up to this point, refrigerate it for a few hours, and then garnish just before serving.
Step 4: Garnish with raspberries and mint sprigs.
Note: The eggs in this recipe are not fully cooked, which may be a concern if you're pregnant or have a compromised immune system.