Preheat oven to 180°C. Grease and line the bases and sides of three 20cm (base measurement) round cake pans.
Combine the strawberry and sugar in a large saucepan over medium-low heat. Cook, stirring occasionally, for 5 mins or until the sugar dissolves and strawberry releases its juice. Increase heat to medium. Bring to a simmer. Cook, stirring occasionally, for a further 10-15 mins or until the mixture reduces by half and thickens. Set the strawberry mixture aside to cool slightly.
Transfer the strawberry mixture to a food processor and process until smooth. Set aside to cool. Reserve ¼ cup (60ml) of the strawberry puree.
Use an electric mixer to beat butter and extra sugar in a large bowl until pale and creamy. Add the eggs, 1 at a time, beating well after each addition. Add combined flour and almond meal and stir to combine. Add the remaining strawberry puree and a little pink food colouring and stir to combine.
Divide the batter evenly among the prepared pans. Smooth the surface. Bake for 30-35 mins or until a skewer inserted in the centres comes out clean. Set aside in the pans for 5 mins to cool slightly before turning onto a wire rack to cool completely.
Meanwhile, place the champagne or sparkling wine in a small saucepan. Bring to a simmer over medium heat. Cook for 5-7 mins or until champagne or sparkling wine reduces to about 2 tbs. Set aside to cool.
Use an electric mixer to beat the extra butter in a medium bowl until very pale. Gradually add the icing sugar, beating well after each addition. Add the champagne or sparkling wine and reserved strawberry puree. Beat until well combined.
Place 1 cake on a serving plate. Spread with a little of the buttercream. Top with another cake. Continue layering with more buttercream and the remaining cake. Spread the top and side of the cake with the remaining buttercream. Use a large palette knife to smooth the top and side. Decorate with the extra strawberries.