This cake is lemony inside and out. The combination of frozen lemonade concentrate and fresh lemon zest give this cake a zingy flavor.

Cake
2 1/2 cups cake flour
2 teaspoons baking powder
1/4 teaspoon salt
1/2 cup plus 2 tablespoons (1 1/4 sticks) unsalted
    butter, room temperature
1 1/3 cups granulated sugar
3 tablespoons frozen lemonade concentrate, thawed
1 tablespoon lemon zest
1 teaspoon vanilla extract
4 large eggs
1 cup whole milk

Frosting
16 ounces cream cheese, room temperature
3/4 cup (1 1/2 sticks) unsalted butter, room temperature
3 cups confectioners' sugar, sifted
2 teaspoons minced lemon zest
1/2 teaspoon vanilla extract
1/2 teaspoon lemon oil

Lemon zest for garnish

Cake: Preheat oven to 350 degrees F. Butter two 9-inch-square nonstick cake pans with 2-inch-high sides; line bottoms with parchment paper; butter paper.

Sift flour, baking powder and salt into medium bowl; set aside.

Using electric stand mixer and paddle attachment, beat butter in large bowl until fluffy. Gradually add sugar, scraping down sides of bowl occasionally and beating until light. Beat in lemonade concentrate, zest and vanilla extract. Beat in eggs one at a time, scrapping down sides occasionally. Continue to beat until mixture is smooth. On low speed beat in dry ingredients alternately with milk in 3 batches, beginning and ending with dry ingredients, until just blended. Divide batter equally between prepared pans.

Bake cakes until tester inserted into center comes out clean, about 25 minutes. Cool cakes in pans on racks.

Frosting: Using electric stand mixer and whisk attachment, beat cream cheese and butter in large bowl until light and fluffy. Gradually beat in sugar, scrapping down sides of bowl occasionally. Beat in zest, vanilla extract and lemon oil until mixture is smooth and fluffy, about 4 minutes.

To Assemble: Turn cakes out onto work surface. Peel off parchment paper. Place one cake layer, flat side up, on platter. Spread with 1 cup frosting. Top with second cake layer, flat side down. spread remaining frosting over top and sides of cake.

Do-ahead tip: Cake can be made 1 day ahead. Cover with cake dome; refrigerate. Let stand at room temperature 2 hours before serving.

Optional garnish: Peel off long strips of lemon zest using zester. Sprinkle zest around edges of cake.