Add butter, sugar and vanilla extract to a bowl and beat with electric mixer until creamy and smooth. Add one egg at a time, beating well after each addition.
Add the buttermilk, vinegar and red food coloring and beat until smooth.
In separate bowl, sift together the flour, baking powder and cocoa. Gradually add the dry ingredients to the wet ingredients, mixing after each addition.
Line a heart-shape cake pan (or two 20 cm (8 inch) round cake pans) with non-stick baking paper. Pour the cake batter into the pan and smooth the top with a palette knife.
Bake for 1 hour or until cooked when tested with a toothpick or skewer. Let cool on a wire wrack.
To prepare the Meringue Icing, combine four egg whites with a pinch of salt. Beat on high with an electric mixer until stiff peaks form. Gradually add the caster sugar, beating on high until the mixture is shiny and smooth.
Slice the cake in half horizontally with a serrated knife and place the base on a serving dish. Spread half of the icing mixture on the base of the cake. Slice the strawberries into halves then into quarters. Arrange the strawberry pieces around the edge of the cake base. Place the other cake half on top of the base and spread with the remaining icing.