Preheat oven to 350 degrees and grease two 9" cake pans (or line a 12-cup muffin pan).

In a large bowl, cream butter until light and fluffy, about 1-2 minutes. Gradually add in sugar, 1/2 cup at a time, beating until well combined.

In a separate bowl, sift together flour, cornstarch, baking powder, and salt. Set aside.

In a small bowl, mix together milk, vanilla extract, and Greek yogurt.

Alternately add dry and wet ingredients into the creamed butter mixture, beginning and ending with the dry ingredients. Stir until just combined.

Beat egg white until they form stiff peaks. Gently fold egg whites into the cake batter.

Pour batter into cake pans, dividing evenly between the two. Bake for 25-30 minutes, or until a cake tester comes out clean. If making cupcakes, bake for 16-17 minutes, or until a cake tester comes out clean.

Cream butter until light and fluffy. Gradually add in powdered sugar, 1 cup at a time (start with 4 cups).

Add in chopped strawberries, vanilla extract, and 2 Tbsp of heavy cream. Beat well, until the strawberries are well combined and the frosting has turned pink in color. If the frosting is too thin, add in the last cup of powdered sugar. If the frosting is too thick, add in the last Tbsp of heavy cream.

Beat heavy cream and powdered sugar until stiff peaks form.

Once the cakes have cooled, place one of the layers on a cake stand or plate. Spread 1/2 - 3/4 cup of frosting on the layer, spreading it evenly to the sides. Place the second layer on top, and use the rest of the frosting to evenly coat the cake.

Pipe whipped cream around the top of the cake and in the center and place a strawberry on each, halves on the outside and a whole in the middle.

If making cupcakes, spread frosting on each cake. Top with a whole strawberry and add sprinkles if desired!

Enjoy!