Divide batter between the two prepared pans, smoothing tops with an offset spatula. Bake for about 30 minutes or until golden and cake tester comes out clean.
Cool pans on wire rack for 15 minutes then remove cakes from pan to cool completely.
Meanwhile, beat whipping cream, sugar and vanilla until soft peaks form, set aside in refrigerator.
Beat butter until light and fluffy, add vanilla and 1 cup icing sugar, beat until combined. Add 1 tbsp of the cream or milk and another cup of icing sugar, mix again, continue with remaining cream or milk and icing sugar, beat until fluffy and smooth.
1 cup (227g) unsalted butter, 1 tsp vanilla, 4 cups (500g) powdered sugar, 3 Tbsp cream or milk
To assemble cake, trim cake domes if needed, spread half of whipping cream onto each cake, sprinkle diced strawberries onto one, top with other, cream side down, pressing slightly.
1 cup of diced strawberries
Spread a thin layer of buttercream all around the outside of the cake, creating a crumb coat. Refrigerate for 30 minutes.
Spread another layer of buttercream on top of the cake, smooth with an offset spatula. Then transfer the remaining buttercream into a pastry bag with an large open star tip like a Wilton 1M. Pipe rosettes all around the sides of the cake. Fill in gaps by pipping a star in between.