Preheat the oven to 200C/400F/Gas 6. Line a cupcake pan with paper cupcake liners.

To make the cupcakes, cream together the butter and sugar with an electric mixer until light and fluffy. Add the egg whites and mix until well combined. Stir in the sour cream, milk, and vanilla extract, mixing just until the batter is smooth.

Sift the flour and baking soda into the batter, and fold in to combine.

Scoop the batter into the cupcake liners to about ¾ full.

Bake the cupcakes at 200C/400F/Gas 6 for 5 minutes, then reduce the heat to 180C/350F/Gas 4 and bake for an additional 9 minutes, or just until the cupcakes have set in the center. To test, insert a toothpick and it should come out clean.

Cool the cupcakes to room temperature on a wire cooling rack/baking rack.

To make the frosting, beat the cream cheese and butter with an electric mixer until smooth. Add the powdered sugar and vanilla; mix well.

Add the cream, one tablespoon at a time, mixing well with an electric mixer until the frosting is creamy and smooth.

Using a knife or small spatula, spread a layer of frosting onto each cupcake.

Arrange the chopped fruit on top of the cupcake as desired.

Serve the cupcakes immediately and enjoy!