1-1/4 cup (300 milliliters) unsalted butter, room temperature
2-1/2 cups (600 milliliters) sugar
3 eggs
3 egg yolks
2 teaspoons (10 milliliters) vanilla extract
4 cups (1 liter) cake flour
1 tablespoon (15 milliliters) baking powder
1/2 teaspoon (2.5 milliliters) salt
1-1/4 cup (300 milliliters) milk
Strawberry preserves (see above)
10 drops (10 milliliters) red food colouring
Vanilla buttercream:
1 cup butter (240 milliliters), room temperature
4 cups (1 liters) icing sugar
2 teaspoons (10 milliliters) vanilla
Directions
To make the strawberry preserves, add strawberries, sugar, and lemon juice to a saucepan and simmer. Stir to break up fruit. Cook until mixture is reduced. It should be thick and syrupy. Set aside to cool.
Preheat oven to 350 F (180 C). To make the cake, cream together butter and sugar in a bowl. Add the eggs, egg yolks, and vanilla and beat in. In a separate bowl, sift the flour with the baking powder and salt. Gradually mix the flour mixture into the butter mixture. Gradually mix in the milk. Divide batter in half. Into one half of the batter, fold in the strawberry preserves and ten drops (ten milliliters) of red food colouring. Pour plain batter into two greased 20 centimeter cake pans. Pour strawberry batter into the remaining two greased 20 centimeter cake pans. Cook for 30 minutes, or until a toothpick inserted into the centre comes out clean. Let cool, then remove from cake pans. Note: put cake pans in the refrigerator to speed up cooling.
To make the icing, cream together butter and sugar. Add vanilla and incorporate.
To assemble, level cakes. Use 15 centimeter, ten centimeter, and five centimeter circular cookie cutters to cut concentric circles out of the cakes. Spread a thin layer of buttercream on the inside ring of all circles. Assemble cake layers by alternating colours. Spread buttercream on one complete layer. Carefully place a different alternating coloured layer on top and spread with buttercream. Repeat until all layers are used up. Spread remaining buttercream over entire cake.