2 cups cake flour
1 1/2 cups sugar
2 teaspoons baking powder
1/2 teaspoon salt
3 large eggs
3/4 cup whole milk
1/2 cup vegetable oil
1/4 cup butter, melted and cooled
1 tablespoon grated lemon rind
1 tablespoon fresh lemon juice
Strawberry-Lemon Filling
1 1/2 cups whipping cream
6 tablespoons sugar
Line a lightly greased 15- x 10-inch jellyroll pan with parchment paper; lightly grease parchment paper.
Combine cake flour and next 3 ingredients in a large bowl.
Whisk together eggs and next 5 ingredients in a medium bowl until blended; whisk into dry ingredients just until blended. Pour batter into prepared pan.
Bake at 350 for 30 minutes or until wooden pick inserted in center comes out clean. Cool cake in pan on wire rack 10 minutes. Invert cake onto a wire rack and remove parchment paper; let cool completely. Transfer cake to large cutting board.
Cut sheet cake in half to make 2 squares. Place 1 cake layer on a serving plate; spread top with half of Strawberry-Lemon Filling. Spread remaining filling over top.
Beat whipping cream and sugar at high speed with an electric mixer until stiff peaks form; spoon into a 1-gallon zip-top plastic freezer bag, press whipped cream into one corner of bag removing excess air and snip a 1/4 inch hole in corner of bag. Pipe whipped cream vertically onto cake sides.
Strawberry-Lemon Filling
1 (16-ounce) package whole frozen strawberries
6 tablespoons sugar, divided
1/4 cup fresh lemon juice
1/4 cup all-purpose flour
Bring strawberries, 4 tablespoons sugar, and lemon juice to a boil a medium saucepan, and cook 5 minutes.
Whisk together remaining 2 tablespoons sugar and flour in a saucepan. Whisk in strawberry mixture; cook over medium heat 5 minutes or until thickened and bubbling around edges. Pour into a glass bowl, cover surface with plastic wrap; chill at least 2 hours.
