Preheat the oven to 350°F. Line a 10x15-inch sheet pan with parchment paper and spray with nonstick spray.

Mix flour and baking powder in a large bowl. Set aside.

Cream butter, sugar, and vanilla in a stand mixer until light and fluffy.

Add egg whites gradually, beating well after each addition.

Alternately add flour mixture and milk to the creamed mixture, starting and ending with flour.

Pour batter into prepared pan and bake for 28-30 minutes, or until a toothpick comes out clean. Cool in pan.

While cake cools, prepare strawberries by mixing with 2 tablespoons of sugar. Set aside.

Make whipped topping by whipping cream cheese and sugar until smooth. Add heavy cream, vanilla, and whip until stiff peaks form.

Slice the cooled cake in half horizontally. Spread strawberries over one half, then top with whipped cream. Cover with the second cake layer and decorate with remaining strawberries and whipped cream.